Systems, devices, and methods for intraphase and interphase balancing in module-based cascaded energy systems

ABSTRACT

Example embodiments of systems, devices, and methods are provided for intraphase and interphase balancing of modular energy systems. The embodiments can be used in a broad variety of mobile and stationary applications in a broad variety of modular cascaded topologies. The embodiments can include the generation of a module status value that is representative of status information collected or determined for the module. The module status value can be an intermediate quantitative representation of the status of each module as it pertains to one or more operating characteristics sought to be balanced by the system. This intermediate quantitative representation can then be used in the generation of a modulation index for the module, which can then be used as part of a larger control technique, such as pulse width modulation, for control and balancing of the system.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation (and claims the benefit ofpriority under 35 USC 120) of U.S. patent application Ser. No.17/487,552, filed Sep. 28, 2021, which claims the benefit of, andpriority to, U.S. Provisional Application No. 63/085,628, filed Sep. 30,2020. The foregoing applications are incorporated by reference herein intheir entirety and for all purposes.

FIELD

The subject matter described herein relates generally to systems,devices, and methods for intraphase and interphase balancing inmodule-based cascaded energy systems usable in mobile and stationaryapplications.

BACKGROUND

Energy systems having multiple energy sources or sinks are commonplacein many industries. One example is the automobile industry. Today'sautomotive technology, as evolved over the past century, ischaracterized, amongst many things, by an interplay of motors,mechanical elements, and electronics. These are the key components thatimpact vehicle performance and driver experience. Motors are of thecombustion or electric type and in almost all cases the rotationalenergy from the motor is delivered via a set of highly sophisticatedmechanical elements, such as clutches, transmissions, differentials,drive shafts, torque tubes, couplers, etc. These parts control to alarge degree torque conversion and power distribution to the wheels andare define the performance of the car and road handling.

An electric vehicle (EV) includes various electrical systems that arerelated to the drivetrain including, among others, the battery pack, thecharger and motor control. High voltage battery packs are typicallyorganized in a serial chain of lower voltage battery modules. Each suchmodule further includes a set of serially connected individual cells anda simple embedded battery management system (BMS) to regulate basic cellrelated characteristics, such as state of charge and voltage.Electronics with more sophisticated capabilities or some form of smartinterconnectedness are absent. As a consequence, any monitoring orcontrol function is handled by a separate system, which, if at allpresent elsewhere in the car, lacks the ability to monitor individualcell health, state of charge, temperature and other performanceimpacting metrics. There is also no ability to meaningfully adjust powerdraw per individual cell in any form. Some of the major consequencesare: (1) the weakest cell constrains the overall performance of theentire battery pack, (2) failure of any cell or module leads to a needfor replacement of the entire pack, (3) battery reliability and safetyare considerably reduced, (4) battery life is limited, (5) thermalmanagement is difficult, (6) battery packs always operate below maximumcapabilities, (7) sudden inrush of regenerative braking derived electricpower cannot be readily stored in the batteries and requires dissipationvia a dump resistor.

Charging circuits for EVs are typically realized in separate on-boardsystems. They stage power coming from outside the EV in the form of anAC signal or a DC signal, convert it to DC and feed it to the batterypack. Charging systems monitor voltage and current and typically supplya steady constant feed. Given the design of the battery packs andtypical charging circuits, there is little ability to tailor chargingflows to individual battery modules based on cell health, performancecharacteristics, temperature, etc. Charging cycles are also typicallylong as the charging systems and battery packs lack the circuitry toallow for pulsed charging or other techniques that would optimize thecharge transfer or total charge achievable.

Conventional controls contain DC to DC conversion stages to adjustbattery pack voltage levels to the bus voltage of the EV's electricalsystem. Motors, in turn, are then driven by simple two-level multiphaseconverters that provide the required AC signal(s) to the electric motor.Each motor is traditionally controlled by a separate controller, whichdrives the motor in a three phase design. Dual motor EVs would requiretwo controllers, while EVs using four in-wheel motors would require fourindividual controllers. The conventional controller design also lacksthe ability to drive next generation motors, such as switch reluctancemotors (SRM), characterized by higher numbers of pole pieces. Adaptationwould require higher phase designs, making the systems more complex andultimately fail to address electric noise and driving performance, suchas high torque ripple and acoustical noise.

Many of these deficiencies apply not only to automobiles but other motordriven vehicles, and also to stationary applications to a significantextent. For these and other reasons, needs exist for improved systems,devices, and methods for energy systems for mobile and stationaryapplications.

SUMMARY

Example embodiments of systems, devices, and methods are provided hereinfor intraphase and interphase balancing of modular energy systems. Theexample embodiments can be used in a broad variety of mobile andstationary applications in a broad variety of modular cascadedtopologies. Example embodiments can include the generation of a modulestatus value that is representative of status information collected ordetermined for the module. The module status value can be anintermediate quantitative representation of the status of each module asit pertains to one or more operating characteristics sought to bebalanced by the system. The embodiments can utilize thresholds todemarcate the severity of an operating characteristic of the module, andmultiple such operating characteristics, like state of charge andtemperature, can be independently weighted to generate a single modulestatus value representative of the overall module status. Thisintermediate quantitative representation can then be used in thegeneration of a modulation index for the module, which can then be usedas part of a larger control technique, such as pulse width modulation,for control and balancing of the system. The example embodiments alsoenable utilization of the module status value for generating arepresentation of the overall health of the array which can then becompared to other arrays of the system for purposes of performinginterphase balancing using and interphase balancing technique, such ascommon mode injection or energy injection from interconnection modules.

Other systems, devices, methods, features and advantages of the subjectmatter described herein will be or will become apparent to one withskill in the art upon examination of the following figures and detaileddescription. It is intended that all such additional systems, methods,features and advantages be included within this description, be withinthe scope of the subject matter described herein, and be protected bythe accompanying claims. In no way should the features of the exampleembodiments be construed as limiting the appended claims, absent expressrecitation of those features in the claims.

BRIEF DESCRIPTION OF FIGURES

The details of the subject matter set forth herein, both as to itsstructure and operation, may be apparent by study of the accompanyingfigures, in which like reference numerals refer to like parts. Thecomponents in the figures are not necessarily to scale, emphasis insteadbeing placed upon illustrating the principles of the subject matter.Moreover, all illustrations are intended to convey concepts, whererelative sizes, shapes and other detailed attributes may be illustratedschematically rather than literally or precisely.

FIGS. 1A-1C are block diagrams depicting example embodiments of amodular energy system.

FIGS. 1D-1E are block diagrams depicting example embodiments of controldevices for an energy system.

FIGS. 1F-1G are block diagrams depicting example embodiments of modularenergy systems coupled with a load and a charge source.

FIGS. 2A-2B are block diagrams depicting example embodiments of a moduleand control system within an energy system.

FIG. 2C is a block diagram depicting an example embodiment of a physicalconfiguration of a module.

FIG. 2D is a block diagram depicting an example embodiment of a physicalconfiguration of a modular energy system.

FIGS. 3A-3C are block diagrams depicting example embodiments of moduleshaving various electrical configurations.

FIGS. 4A-4F are schematic views depicting example embodiments of energysources.

FIGS. 5A-5C are schematic views depicting example embodiments of energybuffers.

FIGS. 6A-6C are schematic views depicting example embodiments ofconverters.

FIGS. 7A-7E are block diagrams depicting example embodiments of modularenergy systems having various topologies.

FIG. 8A is a plot depicting an example output voltage of a module.

FIG. 8B is a plot depicting an example multilevel output voltage of anarray of modules.

FIG. 8C is a plot depicting an example reference signal and carriersignals usable in a pulse width modulation control technique.

FIG. 8D is a plot depicting example reference signals and carriersignals usable in a pulse width modulation control technique.

FIG. 8E is a plot depicting example switch signals generated accordingto a pulse width modulation control technique.

FIG. 8F as a plot depicting an example multilevel output voltagegenerated by superposition of output voltages from an array of modulesunder a pulse width modulation control technique.

FIGS. 9A-9B are block diagrams depicting example embodiments ofcontrollers for a modular energy system.

FIG. 9C is a block diagram depicting an example embodiment of anintraphase controller for a modular energy system.

FIG. 9D is a block diagram depicting an example embodiment of aninterphase controller for a modular energy system.

FIG. 10A is a block diagram depicting an example embodiment of amultiphase modular energy system having interconnection module.

FIG. 10B is a schematic diagram depicting an example embodiment of aninterconnection module in the multiphase embodiment of FIG. 10A.

FIG. 10C is a block diagram depicting an example embodiment of a modularenergy system having two subsystems connected together byinterconnection modules.

FIG. 10D is a block diagram depicting an example embodiment of athree-phase modular energy system having interconnection modulessupplying auxiliary loads.

FIG. 10E is a schematic view depicting an example embodiment of theinterconnection modules in the multiphase embodiment of FIG. 10D.

FIG. 10F is a block diagram depicting another example embodiment of athree-phase modular energy system having interconnection modulessupplying auxiliary loads.

DETAILED DESCRIPTION

Before the present subject matter is described in detail, it is to beunderstood that this disclosure is not limited to the particularembodiments described, as such may, of course, vary. The terminologyused herein is for the purpose of describing particular embodimentsonly, and is not intended to be limiting, since the scope of the presentdisclosure will be limited only by the appended claims.

Examples of Applications

Stationary applications are those in which the modular energy system islocated in a fixed location during use, although it may be capable ofbeing transported to alternative locations when not in use. Themodule-based energy system resides in a static location while providingelectrical energy for consumption by one or more other entities, orstoring or buffering energy for later consumption. Examples ofstationary applications in which the embodiments disclosed herein can beused include, but are not limited to: energy systems for use by orwithin one or more residential structures or locales, energy systems foruse by or within one or more industrial structures or locales, energysystems for use by or within one or more commercial structures orlocales, energy systems for use by or within one or more governmentalstructures or locales (including both military and non-military uses),energy systems for charging the mobile applications described below(e.g., a charge source or a charging station), and systems that convertsolar power, wind, geothermal energy, fossil fuels, or nuclear reactionsinto electricity for storage. Stationary applications often supply loadssuch as grids and microgrids, motors, and data centers. A stationaryenergy system can be used in either a storage or non-storage role.

Mobile applications, sometimes referred to as traction applications, aregenerally ones where a module-based energy system is located on orwithin an entity, and stores and provides electrical energy forconversion into motive force by a motor to move or assist in moving thatentity. Examples of mobile entities with which the embodiments disclosedherein can be used include, but are not limited to, electric and/orhybrid entities that move over or under land, over or under sea, aboveand out of contact with land or sea (e.g., flying or hovering in theair), or through outer space. Examples of mobile entities with which theembodiments disclosed herein can be used include, but are not limitedto, vehicles, trains, trams, ships, vessels, aircraft, and spacecraft.Examples of mobile vehicles with which the embodiments disclosed hereincan be used include, but are not limited to, those having only one wheelor track, those having only two-wheels or tracks, those having onlythree wheels or tracks, those having only four wheels or tracks, andthose having five or more wheels or tracks. Examples of mobile entitieswith which the embodiments disclosed herein can be used include, but arenot limited to, a car, a bus, a truck, a motorcycle, a scooter, anindustrial vehicle, a mining vehicle, a flying vehicle (e.g., a plane, ahelicopter, a drone, etc.), a maritime vessel (e.g., commercial shippingvessels, ships, yachts, boats or other watercraft), a submarine, alocomotive or rail-based vehicle (e.g., a train, a tram, etc.), amilitary vehicle, a spacecraft, and a satellite.

In describing embodiments herein, reference may be made to a particularstationary application (e.g., grid, micro-grid, data centers, cloudcomputing environments) or mobile application (e.g., an electric car).Such references are made for ease of explanation and do not mean that aparticular embodiment is limited for use to only that particular mobileor stationary application. Embodiments of systems providing power to amotor can be used in both mobile and stationary applications. Whilecertain configurations may be more suitable to some applications overothers, all example embodiments disclosed herein are capable of use inboth mobile and stationary applications unless otherwise noted.

Examples of Module-Based Energy Systems

FIG. 1A is a block diagram depicts an example embodiment of amodule-based energy system 100. Here, system 100 includes control system102 communicatively coupled with N converter-source modules 108-1through 108-N, over communication paths or links 106-1 through 106-N,respectively. Modules 108 are configured to store energy and output theenergy as needed to a load 101 (or other modules 108). In theseembodiments, any number of two or more modules 108 can be used (e.g., Nis greater than or equal to two). Modules 108 can be connected to eachother in a variety of manners as will be described in more detail withrespect to FIGS. 7A-7E. For ease of illustration, in FIGS. 1A-1C,modules 108 are shown connected in series, or as a one dimensionalarray, where the Nth module is coupled to load 101.

System 100 is configured to supply power to load 101. Load 101 can beany type of load such as a motor or a grid. System 100 is alsoconfigured to store power received from a charge source. FIG. 1F is ablock diagram depicting an example embodiment of system 100 with a powerinput interface 151 for receiving power from a charge source 150 and apower output interface for outputting power to load 101. In thisembodiment system 100 can receive and store power over interface 151 atthe same time as outputting power over interface 152. FIG. 1G is a blockdiagram depicting another example embodiment of system 100 with aswitchable interface 154. In this embodiment, system 100 can select, orbe instructed to select, between receiving power from charge source 150and outputting power to load 101. System 100 can be configured to supplymultiple loads 101, including both primary and auxiliary loads, and/orreceive power from multiple charge sources 150 (e.g., a utility-operatedpower grid and a local renewable energy source (e.g., solar)).

FIG. 1B depicts another example embodiment of system 100. Here, controlsystem 102 is implemented as a master control device (MCD) 112communicatively coupled with N different local control devices (LCDs)114-1 through 114-N over communication paths or links 115-1 through115-N, respectively. Each LCD 114-1 through 114-N is communicativelycoupled with one module 108-1 through 108-N over communication paths orlinks 116-1 through 116-N, respectively, such that there is a 1:1relationship between LCDs 114 and modules 108.

FIG. 1C depicts another example embodiment of system 100. Here, MCD 112is communicatively coupled with M different LCDs 114-1 to 114-M overcommunication paths or links 115-1 to 115-M, respectively. Each LCD 114can be coupled with and control two or more modules 108. In the exampleshown here, each LCD 114 is communicatively coupled with two modules108, such that M LCDs 114-1 to 114-M are coupled with 2M modules 108-1through 108-2M over communication paths or links 116-1 to 116-2M,respectively.

Control system 102 can be configured as a single device (e.g., FIG. 1A)for the entire system 100 or can be distributed across or implemented asmultiple devices (e.g., FIGS. 1B-1C). In some embodiments, controlsystem 102 can be distributed between LCDs 114 associated with themodules 108, such that no MCD 112 is necessary and can be omitted fromsystem 100.

Control system 102 can be configured to execute control using software(instructions stored in memory that are executable by processingcircuitry), hardware, or a combination thereof. The one or more devicesof control system 102 can each include processing circuitry 120 andmemory 122 as shown here. Example implementations of processingcircuitry and memory are described further below.

Control system 102 can have a communicative interface for communicatingwith devices 104 external to system 100 over a communication link orpath 105. For example, control system 102 (e.g., MCD 112) can outputdata or information about system 100 to another control device 104(e.g., the Electronic Control Unit (ECU) or Motor Control Unit (MCU) ofa vehicle in a mobile application, grid controller in a stationaryapplication, etc.).

Communication paths or links 105, 106, 115, 116, and 118 (FIG. 2B) caneach be wired (e.g., electrical, optical) or wireless communicationpaths that communicate data or information bidirectionally, in parallelor series fashion. Data can be communicated in a standardized (e.g.,IEEE, ANSI) or custom (e.g., proprietary) format. In automotiveapplications, communication paths 115 can be configured to communicateaccording to FlexRay or CAN protocols. Communication paths 106, 115,116, and 118 can also provide wired power to directly supply theoperating power for system 102 from one or more modules 108. Forexample, the operating power for each LCD 114 can be supplied only bythe one or more modules 108 to which that LCD 114 is connected and theoperating power for MCD 112 can be supplied indirectly from one or moreof modules 108 (e.g., such as through a car's power network).

Control system 102 is configured to control one or more modules 108based on status information received from the same or different one ormore of modules 108. Control can also be based on one or more otherfactors, such as requirements of load 101. Controllable aspects include,but are not limited to, one or more of voltage, current, phase, and/oroutput power of each module 108.

Status information of every module 108 in system 100 can be communicatedto control system 102, from which system 102 can independently controlevery module 108-1 . . . 108-N. Other variations are possible. Forexample, a particular module 108 (or subset of modules 108) can becontrolled based on status information of that particular module 108 (orsubset), based on status information of a different module 108 that isnot that particular module 108 (or subset), based on status informationof all modules 108 other than that particular module 108 (or subsetbased on status information of that particular module 108 (or subset)and status information of at least one other module 108 that is not thatparticular module 108 (or subset), or based on status information of allmodules 108 in system 100.

The status information can be information about one or more aspects,characteristics, or parameters of each module 108. Types of statusinformation include, but are not limited to, the following aspects of amodule 108 or one or more components thereof (e.g., energy source,energy buffer, converter, monitor circuitry): State of Charge (SOC)(e.g., the level of charge of an energy source relative to its capacity,such as a fraction or percent) of the one or more energy sources of themodule, State of Health (SOH) (e.g., a figure of merit of the conditionof an energy source compared to its ideal conditions) of the one or moreenergy sources of the module, temperature of the one or more energysources or other components of the module, capacity of the one or moreenergy sources of the module, voltage of the one or more energy sourcesand/or other components of the module, current of the one or more energysources and/or other components of the module, and/or the presence ofabsence of a fault in any one or more of the components of the module.

LCDs 114 can be configured to receive the status information from eachmodule 108, or determine the status information from monitored signalsor data received from or within each module 108, and communicate thatinformation to MCD 112. In some embodiments, each LCD 114 cancommunicate raw collected data to MCD 112, which then algorithmicallydetermines the status information on the basis of that raw data. MCD 112can then use the status information of modules 108 to make controldeterminations accordingly. The determinations may take the form ofinstructions, commands, or other information (such as a modulation indexdescribed herein) that can be utilized by LCDs 114 to either maintain oradjust the operation of each module 108.

For example, MCD 112 may receive status information and assess thatinformation to determine a difference between at least one module 108(e.g., a component thereof) and at least one or more other modules 108(e.g., comparable components thereof). For example, MDC 112 maydetermine that a particular module 108 is operating with one of thefollowing conditions as compared to one or more other modules 108: witha relatively lower or higher SOC, with a relatively lower or higher SOH,with a relatively lower or higher capacity, with a relatively lower orhigher voltage, with a relatively lower or higher current, with arelatively lower or higher temperature, or with or without a fault. Insuch examples, MCD 112 can output control information that causes therelevant aspect (e.g., output voltage, current, power, temperature) ofthat particular module 108 to be reduced or increased (depending on thecondition). In this manner, the utilization of an outlier module 108(e.g., operating with a relatively lower SOC or higher temperature), canbe reduced so as to cause the relevant parameter of that module 108(e.g., SOC or temperature) to converge towards that of one or more othermodules 108.

The determination of whether to adjust the operation of a particularmodule 108 can be made by comparison of the status information topredetermined thresholds, limits, or conditions, and not necessarily bycomparison to statuses of other modules 108. The predeterminedthresholds, limits, or conditions can be static thresholds, limits, orconditions, such as those set by the manufacturer that do not changeduring use. The predetermined thresholds, limits, or conditions can bedynamic thresholds, limits, or conditions, that are permitted to change,or that do change, during use. For example, MCD 112 can adjust theoperation of a module 108 if the status information for that module 108indicates it to be operating in violation (e.g., above or below) of apredetermined threshold or limit, or outside of a predetermined range ofacceptable operating conditions. Similarly, MCD 112 can adjust theoperation of a module 108 if the status information for that module 108indicates the presence of an actual or potential fault (e.g., an alarm,or warning) or indicates the absence or removal of an actual orpotential fault. Examples of a fault include, but are not limited to, anactual failure of a component, a potential failure of a component, ashort circuit or other excessive current condition, an open circuit, anexcessive voltage condition, a failure to receive a communication, thereceipt of corrupted data, and the like. Depending on the type andseverity of the fault, the faulty module's utilization can be decreasedto avoid damaging the module, or the module's utilization can be ceasedaltogether.

MCD 112 can control modules 108 within system 100 to achieve or convergetowards a desired target. The target can be, for example, operation ofall modules 108 at the same or similar levels with respect to eachother, or within predetermined thresholds limits, or conditions. Thisprocess is also referred to as balancing or seeking to achieve balancein the operation or operating characteristics of modules 108. The term“balance” as used herein does not require absolute equality betweenmodules 108 or components thereof, but rather is used in a broad senseto convey that operation of system 100 can be used to actively reducedisparities in operation between modules 108 that would otherwise exist.

MCD 112 can communicate control information to LCD 114 for the purposeof controlling the modules 108 associated with the LCD 114. The controlinformation can be, e.g., a modulation index and a reference signal asdescribed herein, a modulated reference signal, or otherwise. Each LCD114 can use (e.g., receive and process) the control information togenerate switch signals that control operation of one or more components(e.g., a converter) within the associated module(s) 108. In someembodiments, MCD 112 generates the switch signals directly and outputsthem to LCD 114, which relays the switch signals to the intended modulecomponent.

All or a portion of control system 102 can be combined with a systemexternal control device 104 that controls one or more other aspects ofthe mobile or stationary application. When integrated in this shared orcommon control device (or subsystem), control of system 100 can beimplemented in any desired fashion, such as one or more softwareapplications executed by processing circuitry of the shared device, withhardware of the shared device, or a combination thereof. Non-exhaustiveexamples of external control devices 104 include: a vehicular ECU or MCUhaving control capability for one or more other vehicular functions(e.g., motor control, driver interface control, traction control, etc.);a grid or micro-grid controller having responsibility for one or moreother power management functions (e.g., load interfacing, load powerrequirement forecasting, transmission and switching, interface withcharge sources (e.g., diesel, solar, wind), charge source powerforecasting, back up source monitoring, asset dispatch, etc.); and adata center control subsystem (e.g., environmental control, networkcontrol, backup control, etc.).

FIGS. 1D and 1E are block diagrams depicting example embodiments of ashared or common control device (or system) 132 in which control system102 can be implemented. In FIG. 1D, common control device 132 includesmaster control device 112 and external control device 104. Mastercontrol device 112 includes an interface 141 for communication with LCDs114 over path 115, as well as an interface 142 for communication withexternal control device 104 over internal communication bus 136.External control device 104 includes an interface 143 for communicationwith master control device 112 over bus 136, and an interface 144 forcommunication with other entities (e.g., components of the vehicle orgrid) of the overall application over communication path 136. In someembodiments, common control device 132 can be integrated as a commonhousing or package with devices 112 and 104 implemented as discreteintegrated circuit (IC) chips or packages contained therein.

In FIG. 1E, external control device 104 acts as common control device132, with the master control functionality implemented as a componentwithin device 104. This component 112 can be or include software orother program instructions stored and/or hardcoded within memory ofdevice 104 and executed by processing circuitry thereof. The componentcan also contain dedicated hardware. The component can be aself-contained module or core, with one or more internal hardware and/orsoftware interfaces (e.g., application program interface (API)) forcommunication with the operating software of external control device104. External control device 104 can manage communication with LCDs 114over interface 141 and other devices over interface 144. In variousembodiments, device 104/132 can be integrated as a single IC chip, canbe integrated into multiple IC chips in a single package, or integratedas multiple semiconductor packages within a common housing.

In the embodiments of FIGS. 1D and 1E, the master control functionalityof system 102 is shared in common device 132, however, other divisionsof shared control or permitted. For example, part of the master controlfunctionality can be distributed between common device 132 and adedicated MCD 112. In another example, both the master controlfunctionality and at least part of the local control functionality canbe implemented in common device 132 (e.g., with remaining local controlfunctionality implemented in LCDs 114). In some embodiments, all ofcontrol system 102 is implemented in common device (or system) 132. Insome embodiments, local control functionality is implemented within adevice shared with another component of each module 108, such as aBattery Management System (BMS).

Examples of Modules within Cascaded Energy Systems

Module 108 can include one or more energy sources and a powerelectronics converter and, if desired, an energy buffer. FIGS. 2A-2B areblock diagrams depicting additional example embodiments of system 100with module 108 having a power converter 202, an energy buffer 204, andan energy source 206. Converter 202 can be a voltage converter or acurrent converter. The embodiments are described herein with referenceto voltage converters, although the embodiments are not limited to such.Converter 202 can be configured to convert a direct current (DC) signalfrom energy source 204 into an alternating current (AC) signal andoutput it over power connection 110 (e.g., an inverter). Converter 202can also receive an AC or DC signal over connection 110 and apply it toenergy source 204 with either polarity in a continuous or pulsed form.Converter 202 can be or include an arrangement of switches (e.g., powertransistors) such as a half bridge of full bridge (H-bridge). In someembodiments converter 202 includes only switches and the converter (andthe module as a whole) does not include a transformer.

Converter 202 can be also (or alternatively) be configured to perform ACto DC conversion (e.g., a rectifier) such as to charge a DC energysource from an AC source, DC to DC conversion, and/or AC to ACconversion (e.g., in combination with an AC-DC converter). In someembodiments, such as to perform AC-AC conversion, converter 202 caninclude a transformer, either alone or in combination with one or morepower semiconductors (e.g., switches, diodes, thyristors, and the like).In other embodiments, such as those where weight and cost is asignificant factor, converter 202 can be configured to perform theconversions with only power switches, power diodes, or othersemiconductor devices and without a transformer.

Energy source 206 is preferably a robust energy storage device capableof outputting direct current and having an energy density suitable forenergy storage applications for electrically powered devices. The fuelcell can be a single fuel cell, multiple fuel cells connected in seriesor parallel, or a fuel cell module. Two or more energy sources can beincluded in each module, and the two or more sources can include twobatteries of the same or different type, two capacitors of the same ordifferent type, two fuel cells of the same or different type, one ormore batteries combined with one or more capacitors and/or fuel cells,and one or more capacitors combined with one or more fuel cells.

Energy source 206 can be an electrochemical battery, such as a singlebattery cell or multiple battery cells connected together in a batterymodule or array, or any combination thereof. FIGS. 4A-4D are schematicdiagrams depicting example embodiments of energy source 206 configuredas a single battery cell 402 (FIG. 4A), a battery module with a seriesconnection of four cells 402 (FIG. 4B), a battery module with a parallelconnection of single cells 402 (FIG. 4C), and a battery module with aparallel connection with legs having two cells 402 each (FIG. 4D).Examples of battery types are described elsewhere herein.

Energy source 206 can also be a high energy density (HED) capacitor,such as an ultracapacitor or supercapacitor. An HED capacitor can beconfigured as a double layer capacitor (electrostatic charge storage),pseudocapacitor (electrochemical charge storage), hybrid capacitor(electrostatic and electrochemical), or otherwise, as opposed to a soliddielectric type of a typical electrolytic capacitor. The HED capacitorcan have an energy density of 10 to 100 times (or higher) that of anelectrolytic capacitor, in addition to a higher capacity. For example,HED capacitors can have a specific energy greater than 1.0 watt hoursper kilogram (Wh/kg), and a capacitance greater than 10-100 farads (F).As with the batteries described with respect to FIGS. 4A-4D, energysource 206 can be configured as a single HED capacitor or multiple HEDcapacitors connected together in an array (e.g., series, parallel, or acombination thereof).

Energy source 206 can also be a fuel cell. Examples of fuel cellsinclude proton-exchange membrane fuel cells (PEMFC), phosphoric acidfuel cells (PAFC), solid acid fuel cells, alkaline fuel cells, hightemperature fuel cells, solid oxide fuel cells, molten electrolyte fuelcells, and others. As with the batteries described with respect to FIGS.4A-4D, energy source 206 can be configured as a single fuel cell ormultiple fuel cells connected together in an array (e.g., series,parallel, or a combination thereof). The aforementioned examples ofbatteries, capacitors, and fuel cells are not intended to form anexhaustive list, and those of ordinary skill in the art will recognizeother variants that fall within the scope of the present subject matter.

Energy buffer 204 can dampen or filter fluctuations in current acrossthe DC line or link (e.g., +V_(DCL) and −V_(DCL) as described below), toassist in maintaining stability in the DC link voltage. Thesefluctuations can be relatively low (e.g., kilohertz) or high (e.g.,megahertz) frequency fluctuations or harmonics caused by the switchingof converter 202, or other transients. These fluctuations can beabsorbed by buffer 204 instead of being passed to source 206 or to portsIO3 and IO4 of converter 202.

Power connection 110 is a connection for transferring energy or powerto, from and through module 108. Module 108 can output energy fromenergy source 206 to power connection 110, where it can be transferredto other modules of the system or to a load. Module 108 can also receiveenergy from other modules 108 or a charging source (DC charger, singlephase charger, multi-phase charger). Signals can also be passed throughmodule 108 bypassing energy source 206. The routing of energy or powerinto and out of module 108 is performed by converter 202 under thecontrol of LCD 114 (or another entity of system 102).

In the embodiment of FIG. 2A, LCD 114 is implemented as a componentseparate from module 108 (e.g., not within a shared module housing) andis connected to and capable of communication with converter 202 viacommunication path 116. In the embodiment of FIG. 2B, LCD 114 isincluded as a component of module 108 and is connected to and capable ofcommunication with converter 202 via internal communication path 118(e.g., a shared bus or discrete connections). LCD 114 can also becapable of receiving signals from, and transmitting signals to, energybuffer 204 and/or energy source 206 over paths 116 or 118.

Module 108 can also include monitor circuitry 208 configured to monitor(e.g., collect, sense, measure, and/or determine) one or more aspects ofmodule 108 and/or the components thereof, such as voltage, current,temperature or other operating parameters that constitute statusinformation (or can be used to determine status information by, e.g.,LCD 114). A main function of the status information is to describe thestate of the one or more energy sources 206 of the module 108 to enabledeterminations as to how much to utilize the energy source in comparisonto other sources in system 100, although status information describingthe state of other components (e.g., voltage, temperature, and/orpresence of a fault in buffer 204, temperature and/or presence of afault in converter 202, presence of a fault elsewhere in module 108,etc.) can be used in the utilization determination as well. Monitorcircuitry 208 can include one or more sensors, shunts, dividers, faultdetectors, Coulomb counters, controllers or other hardware and/orsoftware configured to monitor such aspects. Monitor circuitry 208 canbe separate from the various components 202, 204, and 206, or can beintegrated with each component 202, 204, and 206 (as shown in FIGS.2A-2B), or any combination thereof. In some embodiments, monitorcircuitry 208 can be part of or shared with a Battery Management System(BMS) for a battery energy source 204. Discrete circuitry is not neededto monitor each type of status information, as more than one type ofstatus information can be monitored with a single circuit or device, orotherwise algorithmically determined without the need for additionalcircuits.

LCD 114 can receive status information (or raw data) about the modulecomponents over communication paths 116, 118. LCD 114 can also transmitinformation to module components over paths 116, 118. Paths 116 and 118can include diagnostics, measurement, protection, and control signallines. The transmitted information can be control signals for one ormore module components. The control signals can be switch signals forconverter 202 and/or one or more signals that request the statusinformation from module components. For example, LCD 114 can cause thestatus information to be transmitted over paths 116, 118 by requestingthe status information directly, or by applying a stimulus (e.g.,voltage) to cause the status information to be generated, in some casesin combination with switch signals that place converter 202 in aparticular state.

The physical configuration or layout of module 108 can take variousforms. In some embodiments, module 108 can include a common housing inwhich all module components, e.g., converter 202, buffer 204, and source206, are housed, along with other optional components such as anintegrated LCD 114. In other embodiments, the various components can beseparated in discrete housings that are secured together. FIG. 2C is ablock diagram depicting an example embodiment of a module 108 having afirst housing 220 that holds an energy source 206 of the module andaccompanying electronics such as monitor circuitry, a second housing 222that holds module electronics such as converter 202, energy buffer 204,and other accompany electronics such as monitor circuitry, and a thirdhousing 224 that holds LCD 114 for the module 108. Electricalconnections between the various module components can proceed throughthe housings 220, 222, 224 and can be exposed on any of the housingexteriors for connection with other devices such as other modules 108 orMCD 112.

Modules 108 of system 100 can be physically arranged with respect toeach other in various configurations that depend on the needs of theapplication and the number of loads. For example, in a stationaryapplication where system 100 provides power for a microgrid, modules 108can be placed in one or more racks or other frameworks. Suchconfigurations may be suitable for larger mobile applications as well,such as maritime vessels. Alternatively, modules 108 can be securedtogether and located within a common housing, referred to as a pack. Arack or a pack may have its own dedicated cooling system shared acrossall modules. Pack configurations are useful for smaller mobileapplications such as electric cars. System 100 can be implemented withone or more racks (e.g., for parallel supply to a microgrid) or one ormore packs (e.g., serving different motors of the vehicle), orcombination thereof. FIG. 2D is a block diagram depicting an exampleembodiment of system 100 configured as a pack with nine modules 108electrically and physically coupled together within a common housing230.

Examples of these and further configurations are described in Int'l.Appl. No. PCT/US20/25366, filed Mar. 27, 2020, titled Module-BasedEnergy Systems Capable of Cascaded and Interconnected Configurations,and Methods Related Thereto, which is incorporated by reference hereinin its entirety for all purposes.

FIGS. 3A-3C are block diagrams depicting example embodiments of modules108 having various electrical configurations. These embodiments aredescribed as having one LCD 114 per module 108, with the LCD 114 housedwithin the associated module, but can be configured otherwise asdescribed herein. FIG. 3A depicts a first example configuration of amodule 108A within system 100. Module 108A includes energy source 206,energy buffer 204, and converter 202A. Each component has powerconnection ports (e.g., terminals, connectors) into which power can beinput and/or from which power can be output, referred to herein as IOports. Such ports can also be referred to as input ports or output portsdepending on the context.

Energy source 206 can be configured as any of the energy source typesdescribed herein (e.g., a battery as described with respect to FIGS.4A-4D, an HED capacitor, a fuel cell, or otherwise). Ports IO1 and IO2of energy source 206 can be connected to ports IO1 and IO2,respectively, of energy buffer 204. Energy buffer 204 can be configuredto buffer or filter high and low frequency energy pulsations arriving atbuffer 204 through converter 202, which can otherwise degrade theperformance of module 108. The topology and components for buffer 204are selected to accommodate the maximum permissible amplitude of thesehigh frequency voltage pulsations. Several (non-exhaustive) exampleembodiments of energy buffer 204 are depicted in the schematic diagramsof FIGS. 5A-5C. In FIG. 5A, buffer 204 is an electrolytic and/or filmcapacitor C_(EB), in FIG. 5B buffer 204 is a Z-source network 710,formed by two inductors L_(EB1) and L_(EB2) and two electrolytic and/orfilm capacitors C_(EB1) and C_(EB2), and in FIG. 5C buffer 204 is aquasi Z-source network 720, formed by two inductors L_(EB1) and L_(EB2),two electrolytic and/or film capacitors C_(EB1) and C_(EB2) and a diodeDEB.

Ports IO3 and IO4 of energy buffer 204 can be connected to ports IO1 andIO2, respectively, of converter 202A, which can be configured as any ofthe power converter types described herein. FIG. 6A is a schematicdiagram depicting an example embodiment of converter 202A configured asa DC-AC converter that can receive a DC voltage at ports IO1 and IO2 andswitch to generate pulses at ports IO3 and IO4. Converter 202A caninclude multiple switches, and here converter 202A includes fourswitches S3, S4, S5, S6 arranged in a full bridge configuration. Controlsystem 102 or LCD 114 can independently control each switch via controlinput lines 118-3 to each gate.

The switches can be any suitable switch type, such as powersemiconductors like the metal-oxide-semiconductor field-effecttransistors (MOSFETs) shown here, insulated gate bipolar transistors(IGBTs), or gallium nitride (GaN) transistors. Semiconductor switchescan operate at relatively high switching frequencies, thereby permittingconverter 202 to be operated in pulse-width modulated (PWM) mode ifdesired, and to respond to control commands within a relatively shortinterval of time. This can provide a high tolerance of output voltageregulation and fast dynamic behavior in transient modes.

In this embodiment, a DC line voltage V_(DCL) can be applied toconverter 202 between ports IO1 and IO2. By connecting V_(DCL) to portsIO3 and IO4 by different combinations of switches S3, S4, S5, S6,converter 202 can generate three different voltage outputs at ports IO3and IO4: +V_(DCL), 0, and −V_(DCL). A switch signal provided to eachswitch controls whether the switch is on (closed) or off (open). Toobtain +V_(DCL), switches S3 and S6 are turned on while S4 and S5 areturned off, whereas −V_(DCL) can be obtained by turning on switches S4and S5 and turning off S3 and S6. The output voltage can be set to zero(including near zero) or a reference voltage by turning on S3 and S5with S4 and S6 off, or by turning on S4 and S6 with S3 and S5 off. Thesevoltages can be output from module 108 over power connection 110. PortsIO3 and IO4 of converter 202 can be connected to (or form) module IOports 1 and 2 of power connection 110, so as to generate the outputvoltage for use with output voltages from other modules 108.

The control or switch signals for the embodiments of converter 202described herein can be generated in different ways depending on thecontrol technique utilized by system 100 to generate the output voltageof converter 202. In some embodiments, the control technique is a PWMtechnique such as space vector pulse-width modulation (SVPWM) orsinusoidal pulse-width modulation (SPWM), or variations thereof. FIG. 8Ais a graph of voltage versus time depicting an example of an outputvoltage waveform 802 of converter 202. For ease of description, theembodiments herein will be described in the context of a PWM controltechnique, although the embodiments are not limited to such. Otherclasses of techniques can be used. One alternative class is based onhysteresis, examples of which are described in Int'l Publ. Nos. WO2018/231810A1, WO 2018/232403A1, and WO 2019/183553A1, which areincorporated by reference herein for all purposes.

Each module 108 can be configured with multiple energy sources 206(e.g., two, three, four, or more). Each energy source 206 of module 108can be controllable (switchable) to supply power to connection 110 (orreceive power from a charge source) independent of the other sources 206of the module. For example, all sources 206 can output power toconnection 110 (or be charged) at the same time, or only one (or asubset) of sources 206 can supply power (or be charged) at any one time.In some embodiments, the sources 206 of the module can exchange energybetween them, e.g., one source 206 can charge another source 206. Eachof the sources 206 can be configured as any energy source describedherein (e.g., battery, HED capacitor, fuel cell). Each of the sources206 can be the same type (e.g., each can be a battery), or a differenttype (e.g., a first source can be a battery and a second source can bean HED capacitor, or a first source can be a battery having a first type(e.g., NMC) and a second source can be a battery having a second type(e.g., LFP).

FIG. 3B is a block diagram depicting an example embodiment of a module108B in a dual energy source configuration with a primary energy source206A and secondary energy source 206B. Ports IO1 and IO2 of primarysource 202A can be connected to ports IO1 and IO2 of energy buffer 204.Module 108B includes a converter 202B having an additional IO port.Ports IO3 and IO4 of buffer 204 can be connected ports IO1 and IO2,respectively, of converter 202B. Ports IO1 and IO2 of secondary source206B can be connected to ports IO5 and IO2, respectively, of converter202B (also connected to port IO4 of buffer 204).

In this example embodiment of module 108B, primary energy source 202A,along with the other modules 108 of system 100, supplies the averagepower needed by the load. Secondary source 202B can serve the functionof assisting energy source 202 by providing additional power at loadpower peaks, or absorbing excess power, or otherwise.

As mentioned both primary source 206A and secondary source 206B can beutilized simultaneously or at separate times depending on the switchstate of converter 202B. If at the same time, an electrolytic and/or afilm capacitor (CEs) can be placed in parallel with source 206B asdepicted in FIG. 4E to act as an energy buffer for the source 206B, orenergy source 206B can be configured to utilize an HED capacitor inparallel with another energy source (e.g., a battery or fuel cell) asdepicted in FIG. 4F.

FIGS. 6B and 6C are schematic views depicting example embodiments ofconverters 202B and 202C, respectively. Converter 202B includes switchcircuitry portions 601 and 602A. Portion 601 includes switches S3through S6 configured as a full bridge in similar manner to converter202A, and is configured to selectively couple IO1 and IO2 to either ofIO3 and IO4, thereby changing the output voltages of module 108B.Portion 602A includes switches S1 and S2 configured as a half bridge andcoupled between ports IO1 and IO2. A coupling inductor L_(C) isconnected between port IO5 and a node1 present between switches S1 andS2 such that switch portion 602A is a bidirectional converter that canregulate (boost or buck) voltage (or inversely current). Switch portion602A can generate two different voltages at node1, which are +V_(DCL2)and 0, referenced to port IO2, which can be at virtual zero potential.The current drawn from or input to energy source 202B can be controlledby regulating the voltage on coupling inductor L_(C), using, forexample, a pulse-width modulation technique or a hysteresis controlmethod for commutating switches S1 and S2. Other techniques can also beused.

Converter 202C differs from that of 202B as switch portion 602B includesswitches S1 and S2 configured as a half bridge and coupled between portsIO5 and IO2. A coupling inductor L_(C) is connected between port IO1 anda node1 present between switches S1 and S2 such that switch portion 602Bis configured to regulate voltage.

Control system 102 or LCD 114 can independently control each switch ofconverters 202B and 202C via control input lines 118-3 to each gate. Inthese embodiments and that of FIG. 6A, LCD 114 (not MCD 112) generatesthe switching signals for the converter switches. Alternatively, MCD 112can generate the switching signals, which can be communicated directlyto the switches, or relayed by LCD 114.

In embodiments where a module 108 includes three or more energy sources206, converters 202B and 202C can be scaled accordingly such that eachadditional energy source 206B is coupled to an additional IO portleading to an additional switch circuitry portion 602A or 602B,depending on the needs of the particular source. For example a dualsource converter 202 can include both switch portions 202A and 202B.

Modules 108 with multiple energy sources 206 are capable of performingadditional functions such as energy sharing between sources 206, energycapture from within the application (e.g., regenerative braking),charging of the primary source by the secondary source even while theoverall system is in a state of discharge, and active filtering of themodule output. The active filtering function can also be performed bymodules having a typical electrolytic capacitor instead of a secondaryenergy source. Examples of these functions are described in more detailin Int'l. Appl. No. PCT/US20/25366, filed Mar. 27, 2020, titledModule-Based Energy Systems Capable of Cascaded and InterconnectedConfigurations, and Methods Related Thereto, and Int'l. Publ. No. WO2019/183553, filed Mar. 22, 2019, titled Systems and Methods for PowerManagement and Control, both of which are incorporated by referenceherein in their entireties for all purposes.

Each module 108 can be configured to supply one or more auxiliary loadswith its one or more energy sources 206. Auxiliary loads are loads thatrequire lower voltages than the primary load 101. Examples of auxiliaryloads can be, for example, an on-board electrical network of an electricvehicle, or an HVAC system of an electric vehicle. The load of system100 can be, for example, one of the phases of the electric vehicle motoror electrical grid. This embodiment can allow a complete decouplingbetween the electrical characteristics (terminal voltage and current) ofthe energy source and those of the loads.

FIG. 3C is a block diagram depicting an example embodiment of a module108C configured to supply power to a first auxiliary load 301 and asecond auxiliary load 302, where module 108C includes an energy source206, energy buffer 204, and converter 202B coupled together in a mannersimilar to that of FIG. 3B. First auxiliary load 301 requires a voltageequivalent to that supplied from source 206. Load 301 is coupled to IOports 3 and 4 of module 108C, which are in turn coupled to ports IO1 andIO2 of source 206. Source 206 can output power to both power connection110 and load 301. Second auxiliary load 302 requires a constant voltagelower than that of source 206. Load 302 is coupled to IO ports 5 and 6of module 108C, which are coupled to ports IO5 and IO2, respectively, ofconverter 202B. Converter 202B can include switch portion 602 havingcoupling inductor L_(C) coupled to port IO5 (FIG. 6B). Energy suppliedby source 206 can be supplied to load 302 through switch portion 602 ofconverter 202B. It is assumed that load 302 has an input capacitor (acapacitor can be added to module 108C if not), so switches S1 and S2 canbe commutated to regulate the voltage on and current through couplinginductor L_(C) and thus produce a stable constant voltage for load 302.This regulation can step down the voltage of source 206 to the lowermagnitude voltage is required by load 302.

Module 108C can thus be configured to supply one or more first auxiliaryloads in the manner described with respect to load 301, with the one ormore first loads coupled to IO ports 3 and 4. Module 108C can also beconfigured to supply one or more second auxiliary loads in the mannerdescribed with respect to load 302. If multiple second auxiliary loads302 are present, then for each additional load 302 module 108C can bescaled with additional dedicated module output ports (like 5 and 6), anadditional dedicated switch portion 602, and an additional converter IOport coupled to the additional portion 602.

Energy source 206 can thus supply power for any number of auxiliaryloads (e.g., 301 and 302), as well as the corresponding portion ofsystem output power needed by primary load 101. Power flow from source206 to the various loads can be adjusted as desired.

Module 108 can be configured as needed with two or more energy sources206 (FIG. 3B) and to supply first and/or second auxiliary loads (FIG.3C) through the addition of a switch portion 602 and converter port IO5for each additional source 206B or second auxiliary load 302. Additionalmodule IO ports (e.g., 3, 4, 5, 6) can be added as needed. Module 108can also be configured as an interconnection module to exchange energy(e.g., for balancing) between two or more arrays, two or more packs, ortwo or more systems 100 as described further herein. Thisinterconnection functionality can likewise be combined with multiplesource and/or multiple auxiliary load supply capabilities.

Control system 102 can perform various functions with respect to thecomponents of modules 108A, 108B, and 108C. These functions can includemanagement of the utilization (amount of use) of each energy source 206,protection of energy buffer 204 from over-current, over-voltage and hightemperature conditions, and control and protection of converter 202.

For example, to manage (e.g., adjust by increasing, decreasing, ormaintaining) utilization of each energy source 206, LCD 114 can receiveone or more monitored voltages, temperatures, and currents from eachenergy source 206 (or monitor circuitry). The monitored voltages can beat least one of, preferably all, voltages of each elementary componentindependent of the other components (e.g., each individual battery cell,HED capacitor, and/or fuel cell) of the source 206, or the voltages ofgroups of elementary components as a whole (e.g., voltage of the batteryarray, HED capacitor array, and/or fuel cell array). Similarly themonitored temperatures and currents can be at least one of, preferablyall, temperatures and currents of each elementary component independentof the other components of the source 206, or the temperatures andcurrents of groups of elementary components as a whole, or anycombination thereof. The monitored signals can be status information,with which LCD 114 can perform one or more of the following: calculationor determination of a real capacity, actual State of Charge (SOC) and/orState of Health (SOH) of the elementary components or groups ofelementary components; set or output a warning or alarm indication basedon monitored and/or calculated status information; and/or transmissionof the status information to MCD 112. LCD 114 can receive controlinformation (e.g., a modulation index, synchronization signal) from MCD112 and use this control information to generate switch signals forconverter 202 that manage the utilization of the source 206.

To protect energy buffer 204, LCD 114 can receive one or more monitoredvoltages, temperatures, and currents from energy buffer 204 (or monitorcircuitry). The monitored voltages can be at least one of, preferablyall, voltages of each elementary component of buffer 204 (e.g., ofC_(EB), C_(EB1), C_(EB2), L_(EB1), L_(EB2), DEB) independent of theother components, or the voltages of groups of elementary components orbuffer 204 as a whole (e.g., between IO1 and IO2 or between IO3 andIO4). Similarly the monitored temperatures and currents can be at leastone of, preferably all, temperatures and currents of each elementarycomponent of buffer 204 independent of the other components, or thetemperatures and currents of groups of elementary components or ofbuffer 204 as a whole, or any combination thereof. The monitored signalscan be status information, with which LCD 114 can perform one or more ofthe following: set or output a warning or alarm indication; communicatethe status information to MCD 112; or control converter 202 to adjust(increase or decrease) the utilization of source 206 and module 108 as awhole for buffer protection.

To control and protect converter 202, LCD 114 can receive the controlinformation from MCD 112 (e.g., a modulated reference signal, or areference signal and a modulation index), which can be used with a PWMtechnique in LCD 114 to generate the control signals for each switch(e.g., S1 through S6). LCD 114 can receive a current feedback signalfrom a current sensor of converter 202, which can be used forovercurrent protection together with one or more fault status signalsfrom driver circuits (not shown) of the converter switches, which cancarry information about fault statuses (e.g., short circuit or opencircuit failure modes) of all switches of converter 202. Based on thisdata, LCD 114 can make a decision on which combination of switchingsignals to be applied to manage utilization of module 108, andpotentially bypass or disconnect converter 202 (and the entire module108) from system 100.

If controlling a module 108C that supplies a second auxiliary load 302,LCD 114 can receive one or more monitored voltages (e.g., the voltagebetween IO ports 5 and 6) and one or more monitored currents (e.g., thecurrent in coupling inductor L_(C), which is a current of load 302) inmodule 108C. Based on these signals, LCD 114 can adjust the switchingcycles (e.g., by adjustment of modulation index or reference waveform)of S1 and S2 to control (and stabilize) the voltage for load 302.

Examples of Cascaded Energy System Topologies

Two or more modules 108 can be coupled together in a cascaded array thatoutputs a voltage signal formed by a superposition of the discretevoltages generated by each module 108 within the array. FIG. 7A is ablock diagram depicting an example embodiment of a topology for system100 where N modules 108-1, 108-2 . . . 108-N are coupled together inseries to form a serial array 700. In this and all embodiments describedherein, N can be any integer greater than one. Array 700 includes afirst system IO port SIO1 and a second system IO port SIO2 across whichis generated an array output voltage. Array 700 can be used as a DC orsingle phase AC energy source for DC or AC single-phase loads, which canbe connected to SIO1 and SIO2 of array 700. FIG. 8A is a plot of voltageversus time depicting an example output signal 801 produced by a singlemodule 108 having a 48 volt energy source. FIG. 8B is a plot of voltageversus time depicting an example single phase AC output signal 802generated by array 700 having six 48V modules 108 coupled in series.

System 100 can be arranged in a broad variety of different topologies tomeet varying needs of the applications. System 100 can providemulti-phase power (e.g., two-phase, three-phase, four-phase, five-phase,six-phase, etc.) to a load by use of multiple arrays 700, where eacharray can generate an AC output signal having a different phase angle.

FIG. 7B is a block diagram depicting system 100 with two arrays 700-PAand 700-PB coupled together. Each array 700 is one-dimensional, formedby a series connection of N modules 108. The two arrays 700-PA and700-PB can each generate a single-phase AC signal, where the two ACsignals have different phase angles PA and PB (e.g., 180 degrees apart).IO port 1 of module 108-1 of each array 700-PA and 700-PB can form or beconnected to system IO ports SIO1 and SIO2, respectively, which in turncan serve as a first output of each array that can provide two phasepower to a load (not shown). Or alternatively ports SIO1 and SIO2 can beconnected to provide single phase power from two parallel arrays. IOport 2 of module 108-N of each array 700-PA and 700-PB can serve as asecond output for each array 700-PA and 700-PB on the opposite end ofthe array from system IO ports SIO1 and SIO2, and can be coupledtogether at a common node and optionally used for an additional systemIO port SIO3 if desired, which can serve as a neutral. This common nodecan be referred to as a rail, and IO port 2 of modules 108-N of eacharray 700 can be referred to as being on the rail side of the arrays.

FIG. 7C is a block diagram depicting system 100 with three arrays700-PA, 700-PB, and 700-PC coupled together. Each array 700 isone-dimensional, formed by a series connection of N modules 108. Thethree arrays 700-1 and 700-2 can each generate a single-phase AC signal,where the three AC signals have different phase angles PA, PB, PC (e.g.,120 degrees apart). IO port 1 of module 108-1 of each array 700-PA,700-PB, and 700-PC can form or be connected to system IO ports SIO1,SIO2, and SIO3, respectively, which in turn can provide three phasepower to a load (not shown). IO port 2 of module 108-N of each array700-PA, 700-PB, and 700-PC can be coupled together at a common node andoptionally used for an additional system IO port SIO4 if desired, whichcan serve as a neutral.

The concepts described with respect to the two-phase and three-phaseembodiments of FIGS. 7B and 7C can be extended to systems 100 generatingstill more phases of power. For example, a non-exhaustive list ofadditional examples includes: system 100 having four arrays 700, each ofwhich is configured to generate a single phase AC signal having adifferent phase angle (e.g., 90 degrees apart): system 100 having fivearrays 700, each of which is configured to generate a single phase ACsignal having a different phase angle (e.g., 72 degrees apart); andsystem 100 having six arrays 700, each array configured to generate asingle phase AC signal having a different phase angle (e.g., 60 degreesapart).

System 100 can be configured such that arrays 700 are interconnected atelectrical nodes between modules 108 within each array. FIG. 7D is ablock diagram depicting system 100 with three arrays 700-PA, 700-PB, and700-PC coupled together in a combined series and delta arrangement. Eacharray 700 includes a first series connection of M modules 108, where Mis two or greater, coupled with a second series connection of N modules108, where N is two or greater. The delta configuration is formed by theinterconnections between arrays, which can be placed in any desiredlocation. In this embodiment, IO port 2 of module 108-(M+N) of array700-PC is coupled with IO port 2 of module 108-M and IO port 1 of module108-(M+1) of array 700-PA, IO port 2 of module 108-(M+N) of array 700-PBis coupled with IO port 2 of module 108-M and IO port 1 of module108-(M+1) of array 700-PC, and IO port 2 of module 108-(M+N) of array700-PA is coupled with IO port 2 of module 108-M and IO port 1 of module108-(M+1) of array 700-PB.

FIG. 7E is a block diagram depicting system 100 with three arrays700-PA, 700-PB, and 700-PC coupled together in a combined series anddelta arrangement. This embodiment is similar to that of FIG. 7D exceptwith different cross connections. In this embodiment, IO port 2 ofmodule 108-M of array 700-PC is coupled with IO port 1 of module 108-1of array 700-PA, IO port 2 of module 108-M of array 700-PB is coupledwith IO port 1 of module 108-1 of array 700-PC, and IO port 2 of module108-M of array 700-PA is coupled with IO port 1 of module 108-1 of array700-PB. The arrangements of FIGS. 7D and 7E can be implemented with aslittle as two modules in each array 700. Combined delta and seriesconfigurations enable an effective exchange of energy between allmodules 108 of the system (interphase balancing) and phases of powergrid or load, and also allows reducing the total number of modules 108in an array 700 to obtain the desired output voltages.

In the embodiments described herein, although it is advantageous for thenumber of modules 108 to be the same in each array 700 within system100, such is not required and different arrays 700 can have differingnumbers of modules 108. Further, each array 700 can have modules 108that are all of the same configuration (e.g., all modules are 108A, allmodules are 108B, all modules are 108C, or others) or differentconfigurations (e.g., one or more modules are 108A, one or more are108B, and one or more are 108C, or otherwise). As such, the scope oftopologies of system 100 covered herein is broad.

Example Embodiments of Control Methodologies

As mentioned, control of system 100 can be performed according tovarious methodologies, such as hysteresis or PWM. Several examples ofPWM include space vector modulation and sine pulse width modulation,where the switching signals for converter 202 are generated with a phaseshifted carrier technique that continuously rotates utilization of eachmodule 108 to equally distribute power among them.

FIGS. 8C-8F are plots depicting an example embodiment of a phase-shiftedPWM control methodology that can generate a multilevel output PWMwaveform using incrementally shifted two-level waveforms. An X-level PWMwaveform can be created by the summation of (X−1)/2 two-level PWMwaveforms. These two-level waveforms can be generated by comparing areference waveform Vref to carriers incrementally shifted by 360°/(X−1).The carriers are triangular, but the embodiments are not limited tosuch. A nine-level example is shown in FIG. 8C (using four modules 108).The carriers are incrementally shifted by 360°/(9−1)=45° and compared toVref. The resulting two-level PWM waveforms are shown in FIG. 8E. Thesetwo-level waveforms may be used as the switching signals forsemiconductor switches (e.g., S1 though S6) of converters 202. As anexample with reference to FIG. 8E, for a one-dimensional array 700including four modules 108 each with a converter 202, the 0° signal isfor control of S3 and the 180° signal for S6 of the first module 108-1,the 45° signal is for S3 and the 225° signal for S6 of the second module108-2, the 90 signal is for S3 and the 270 signal is for S6 of the thirdmodule 108-3, and the 135 signal is for S3 and the 315 signal is for S6of the fourth module 108-4. The signal for S3 is complementary to S4 andthe signal for S5 is complementary to S6 with sufficient dead-time toavoid shoot through of each half-bridge. FIG. 8F depicts an examplesingle phase AC waveform produced by superposition (summation) of outputvoltages from the four modules 108.

An alternative is to utilize both a positive and a negative referencesignal with the first (N−1)/2 carriers. A nine-level example is shown inFIG. 8D. In this example, the 0° to 135° switching signals (FIG. 8E) aregenerated by comparing +Vref to the 0° to 135° carriers of FIG. 8D andthe 180° to 315° switching signals are generated by comparing −Vref tothe 0° to 135° carriers of FIG. 8D. However, the logic of the comparisonin the latter case is reversed. Other techniques such as a state machinedecoder may also be used to generate gate signals for the switches ofconverter 202.

In multi-phase system embodiments, the same carriers can be used foreach phase, or the set of carriers can be shifted as a whole for eachphase. For example, in a three phase system with a single referencevoltage (Vref), each array 700 can use the same number of carriers withthe same relative offsets as shown in FIGS. 8C and 8D, but the carriersof the second phase are shift by 120 degrees as compared to the carriersof the first phase, and the carriers of the third phase are shifted by240 degrees as compared to the carriers of the first phase. If adifferent reference voltage is available for each phase, then the phaseinformation can be carried in the reference voltage and the samecarriers can be used for each phase. In many cases the carrierfrequencies will be fixed, but in some example embodiments, the carrierfrequencies can be adjusted, which can help to reduce losses in EVmotors under high current conditions.

The appropriate switching signals can be provided to each module bycontrol system 102. For example, MCD 112 can provide Vref and theappropriate carrier signals to each LCD 114 depending upon the module ormodules 108 that LCD 114 controls, and the LCD 114 can then generate theswitching signals. Or all LCDs 114 in an array can be provided with allcarrier signals and the LCD can select the appropriate carrier signals.

The relative utilizations of each module 108 can adjusted based onstatus information to perform balancing or of one or more parameters asdescribed herein. Balancing of parameters can involve adjustingutilization to minimize parameter divergence over time as compared to asystem where individual module utilization adjustment is not performed.The utilization can be the relative amount of time a module 108 isdischarging when system 100 is in a discharge state, or the relativeamount of time a module 108 is charging when system 100 is in a chargestate.

As described herein, modules 108 can be balanced with respect to othermodules in an array 700, which can be referred to as intra-array orintraphase balancing, and different arrays 700 can be balanced withrespect to each other, which can be referred to as interarray orinterphase balancing. Arrays 700 of different subsystems can also bebalanced with respect to each other. Control system 102 cansimultaneously perform any combination of intraphase balancing,interphase balancing, utilization of multiple energy sources within amodule, active filtering, and auxiliary load supply.

FIG. 9A is a block diagram depicting an example embodiment of an arraycontroller 900 of control system 102 for a single-phase AC or DC array.Array controller 900 can include a peak detector 902, a divider 904, andan intraphase (or intra-array) balance controller 906. Array controller900 can receive a reference voltage waveform (Vr) and status informationabout each of the N modules 108 in the array (e.g., state of charge(SOCi), temperature (Ti), capacity (Qi), and voltage (Vi)) as inputs,and generate a normalized reference voltage waveform (Vrn) andmodulation indexes (Mi) as outputs. Peak detector 902 detects the peak(Vpk) of Vr, which can be specific to the phase that controller 900 isoperating with and/or balancing. Divider 904 generates Vrn by dividingVr by its detected Vpk. Intraphase balance controller 906 uses Vpk alongwith the status information (e.g., SOCi, Ti, Qi, Vi, etc.) to generatemodulation indexes Mi for each module 108 within the array 700 beingcontrolled.

The modulation indexes and Vrn can be used to generate the switchingsignals for each converter 202. The modulation index can be a numberbetween zero and one (inclusive of zero and one). For a particularmodule 108, the normalized reference Vrn can be modulated or scaled byMi, and this modulated reference signal (Vrnm) can be used as Vref (or−Vref) according to the PWM technique described with respect to FIGS.8C-8F, or according to other techniques. In this manner, the modulationindex can be used to control the PWM switching signals provided to theconverter switching circuitry (e.g., S3-S6 or S1-S6), and thus regulatethe operation of each module 108. For example, a module 108 beingcontrolled to maintain normal or full operation may receive an Mi ofone, while a module 108 being controlled to less than normal or fulloperation may receive an Mi less than one, and a module 108 controlledto cease power output may receive an Mi of zero. This operation can beperformed in various ways by control system 102, such as by MCD 112outputting Vrn and Mi to the appropriate LCDs 114 for modulation andswitch signal generation, by MCD 112 performing modulation andoutputting the modulated Vrnm to the appropriate LCDs 114 for switchsignal generation, or by MCD 112 performing modulation and switch signalgeneration and outputting the switch signals to the LCDs or theconverters 202 of each module 108 directly. Vrn can be sent continuallywith Mi sent at regular intervals, such as once for every period of theVrn, or one per minute, etc.

Controller 906 can generate an Mi for each module 108 using any type orcombination of types of status information (e.g., SOC, temperature (T),Q, SOH, voltage, current) described herein. For example, when using SOCand T, a module 108 can have a relatively high Mi if SOC is relativelyhigh and temperature is relatively low as compared to other modules 108in array 700. If either SOC is relatively low or T is relatively high,then that module 108 can have a relatively low Mi, resulting in lessutilization than other modules 108 in array 700. Controller 906 candetermine Mi such that the sum of module voltages does not exceed Vpk.For example, Vpk can be the sum of the products of the voltage of eachmodule's source 206 and Mi for that module (e.g., Vpk=M₁V₁+M₂V₂+M₃V₃ . .. +M_(N)V_(N), etc). A different combination of modulation indexes, andthus respective voltage contributions by the modules, may be used butthe total generated voltage should remain the same.

Controller 900 can control operation, to the extent it does not preventachieving the power output requirements of the system at any one time(e.g., such as during maximum acceleration of an EV), such that SOC ofthe energy source(s) in each module 108 remains balanced or converges toa balanced condition if they are unbalanced, and/or such thattemperature of the energy source(s) or other component (e.g., energybuffer) in each module remains balanced or converges to a balancedcondition if they are unbalanced. Power flow in and out of the modulescan be regulated such that a capacity difference between sources doesnot cause an SOC deviation. Balancing of SOC and temperature canindirectly cause some balancing of SOH. Voltage and current can bedirectly balanced if desired, but in many embodiments the main goal ofthe system is to balance SOC and temperature, and balancing of SOC canlead to balance of voltage and current in a highly symmetric systemswhere modules are of similar capacity and impedance.

Since balancing all parameters may not be possible at the same time(e.g., balancing of one parameter may further unbalance anotherparameter), a combination of balancing any two or more parameters (SOC,T, Q, SOH, V, I) may be applied with priority given to either onedepending on the requirements of the application. Priority in balancingcan be given to SOC over other parameters (T, Q, SOH, V, I), withexceptions made if one of the other parameters (T, Q, SOH, V, I) reachesa severe unbalanced condition outside a threshold.

Balancing between arrays 700 of different phases (or arrays of the samephase, e.g., if parallel arrays are used) can be performed concurrentlywith intraphase balancing. FIG. 9B depicts an example embodiment of anΩ-phase (or Ω-array) controller 950 configured for operation in anΩ-phase system 100, having at least Ω arrays 700, where Ω is any integergreater than one. Controller 950 can include one interphase (orinterarray) controller 910 and Ω intraphase balance controllers 906-PA .. . 906-PΩ for phases PA through PΩ, as well as peak detector 902 anddivider 904 (FIG. 9A) for generating normalized references VrnPA throughVrnPΩ from each phase-specific reference VrPA through VrPΩ. Intraphasecontrollers 906 can generate Mi for each module 108 of each array 700 asdescribed with respect to FIG. 9A. Interphase balance controller 910 isconfigured or programmed to balance aspects of modules 108 across theentire multi-dimensional system, for example, between arrays ofdifferent phases. This may be achieved through injecting common mode tothe phases (e.g., neutral point shifting) or through the use ofinterconnection modules (described herein) or through both. Common modeinjection involves introducing a phase and amplitude shift to thereference signals VrPA through VrPΩ to generate normalized waveformsVrnPA through VrnPΩ to compensate for unbalance in one or more arrays,and is described further in Int'l. Appl. No. PCT/US20/25366 incorporatedherein. For example, if a determination is made to lower the energyoutput of the modules in phase A by 10%, then a component equal to 10%of VrnA can be subtracted from VrnA, and this same 10% component (e.g.,the common mode) of VrnA can also be subtracted from VrnB and VrnC,which will shift the neutral point towards A. As mentioned above, thiscan occur at the same time as intraphase balancing is being performed.

FIG. 9C is a block diagram depicting an example embodiment of intraphasebalance controller 906 configured to generate modulation indexes foreach module of an array 700. This controller 906 can be implemented incontrol system 102 multiple times, once for each array or phase beingcontrolled. In this embodiment, three instances of controller 906 areshown, one for each array of a three phase system (PA, PB, PC).Alternatively controller 906 can be a single controller that determinesmodulation indexes for the modules of all arrays sequentially.

In this embodiment, status information that includes an SOC value foreach module, a temperature (T) for each module, and a capacity (Q) foreach module, is input to a module status calculation section 920 thatdetermines a module status value (MSi) for each module of the array 700.The status information can be measured directly or estimated with amodel. MSi is a quantitative representation of the state of the moduleas it pertains to an operating characteristic of the system that isbeing balanced (e.g., SOC and/or temperature, others). The MSi values ofthe modules are used to compare each module to assess their relativecondition in terms of how much voltage the module can generate andshould generate in order to converge towards balanced operation. Section920 can generate MSi based on an evaluation of the values in eachparameter category (SOC, T, Q) of status information. MSi can be asingle value that is representative of these multiple parameters of SOC,T, and Q for each module. Each parameter can be weighted such that aparameter that is close to a threshold, indicative of low status or poorhealth, is given greater weight than a parameter that is further fromits threshold. For example, a first module with a relatively low SOCvalue can have an MSi that is larger than a second module with a higherSOC, if T and Q are equal between modules. A first module with arelatively low SOC value can have an MSi that is smaller than a secondmodule with a higher SOC, if the temperature of the second module ismuch closer to a maximum temperature threshold than the temperature ofthe first module. Multiple thresholds can be used for each parametercategory. For example, a temperature that is beneath a first temperaturethreshold (Tthld) may be weighted minimally or not at all, a temperaturethat slightly exceeds Tthld may be weighted relatively higher, and atemperature that is above Tthld and at or near a maximum temperaturethreshold (Tmax) may be weighted relatively higher still. Similarly, oneor more thresholds can be used for SOC and Q, and any other statusinformation implemented in the embodiment.

The generated MSi values are then passed from section 920 to modulationindex calculation section 922 which is configured to generate amodulation index (Mi) for each module using these MSi values. Section922 can generate each Mi by distributing a voltage requirement for thearray across all of the modules of the array using these MSi values. Forexample, the voltage requirement can be the detected peak voltage (Vpk)from the reference signal (Vr) for the array. Section 922 can utilize apresent voltage Vi of each module (the available sources 206 of themodule) and allocate some or all of the Vi to reach the voltagerequirement (e.g., Vpk) for the array. The determination of how much ofthe Vi to allocate is made according to the MSi of the module, withthose modules having better status (as reflected in more robust MSivalues) being allocated a greater portion of the available Vi than thosemodules having relatively lesser status. The allocation is quantified inthe determined Mi for each module. Section 922 can utilize a maxmodulation index value (Mmax) to represent the maximum Mi a module canhave in embodiments where this value is less than 100%, e.g., less thanone. Using an Mmax that is less than 100% can assist in maintaining aminimal pulse width in the PWM process.

The Mi values for each module in the array 700 are then passed to amodulation section 924, which modulates the normalized reference signal(Vrn) for the array by the modulation index, separately for each module,to generate a modulated reference signal (REFi) specific to each module.This modulated reference signal REFi can be used to generate theswitching signals for the converter of the module (e.g., as Vref in theembodiments of FIGS. 8C-8D). As described herein, section 924 can beperformed in controller 906 (e.g., in MCD 112) such that REFi is sentdirectly to each module (e.g., LCD 114) as shown here, or Vrn for thearray and Mi can be sent to the appropriate modules in REFi can begenerated locally at the module (e.g., by LCD 114).

FIG. 9D is a block diagram depicting an example embodiment of interphasebalance controller 910 configured to perform interphase balancing inembodiments with multiple arrays. In this embodiment controller 910 is athree-phase controller and receives reference signals VrPA, VrPB, andVrPC for the three arrays from a motor control unit 931. Controller 910includes a space vector common mode calculation section 934 and abalancing common mode calculation section 936. Space vector section 934evaluates the reference signals VrPA, VrPB, and VrPC and determines afirst compensatory voltage signal (e.g., common mode) which is theninjected to the three reference signals by combination section 938. Thecompensatory voltage signal improves the quality of the AC referencesignals by decreasing total harmonic distortion (THD) and also utilizethe maximum line voltage that can be generated by the converter. Anexample of an equation performed by section 934 to generate thecompensatory voltage signal (Vcm) is set forth in (1).

Vcm=−(max(VrPA,VrPB,VrPC)+min(VrA,VrB,VrC))/2  (1)

Combination section 938 can also inject a common mode signal generatedby section 936 for interphase balancing through neutral point shifting.Section 936 can assess whether a difference in status exists between thethree arrays and, if so, generate a second compensatory voltage signal,based on the assessed difference, that can be injected to referencesignals VrPA, VrPB, and VrPC by combination section 938. Section 936 canutilize a metric that represents the overall status of each array forassessing whether a difference exists. In this embodiment, summations ofthe module status values for each array (ΣMS_(PA), ΣMS_(PB), ΣMS_(PC))can be generated by control system 102 (e.g., MCD 112) and input tosection 936 for use in the comparison. Using this information, adetermination can be made whether a sufficient difference in arraystatus exists (e.g., whether the difference between summations exceeds aminimum threshold), and if so, a common mode signal of the appropriateamplitude and phase is generated and output to section 938 forintroduction of that common mode signal to all three reference signals.The common mode injection will shift the neutral point towards the arrayhaving the lowest overall status or health, thus allowing theutilization of that array to be reduced as compared to the other arrays.In a three or more phase example, the shift the neutral point can betowards either one array or multiple arrays in order to perform the mosteffective balancing.

Section 938 outputs the reference signals with any common modemodification (Vr′PA, Vr′PB, and Vr′PC) for normalization by peakdetection section 902 and divider 904. The determined peak voltages(Vpk,PA, Vpk,PB, Vpk,PC) can be output to section 922 of controller 906for use in generating the modulation indexes, and the resultingnormalized reference signals (RefN_(PA), RefN_(PB), RefN_(PC)) can beoutput to modulation section 924 for generating the modulated referencesignals for each module (REFi). The interphase controller 910 can alsoutilize module status values as described here for interphase balancingwith energy injection from IC modules as described below.

Controllers 900 and 950 (as well as balance controllers 906 and 910) canbe implemented in hardware, software or a combination thereof withincontrol system 102. Controllers 900 and 950 can be implemented withinMCD 112, distributed partially or fully among LCDs 114, or may beimplemented as discrete controllers independent of MCD 112 and LCDs 114.

Example Embodiments of Interconnection (IC) Modules

Modules 108 can be connected between the modules of different arrays 700for the purposes of exchanging energy between the arrays, acting as asource for an auxiliary load, or both. Such modules are referred toherein as interconnection (IC) modules 108IC. IC module 108IC can beimplemented in any of the already described module configurations (108A,108B, 108C) and others to be described herein. IC modules 108IC caninclude any number of one or more energy sources, an optional energybuffer, switch circuitry for supplying energy to one or more arraysand/or for supplying power to one or more auxiliary loads, controlcircuitry (e.g., a local control device), and monitor circuitry forcollecting status information about the IC module itself or its variousloads (e.g., SOC of an energy source, temperature of an energy source orenergy buffer, capacity of an energy source, SOH of an energy source,voltage and/or current measurements pertaining to the IC module, voltageand/or current measurements pertaining to the auxiliary load(s), etc.).

FIG. 10A is a block diagram depicting an example embodiment of a system100 capable of producing Ω-phase power with Ω arrays 700-PA through700-PΩ, where Ω can be any integer greater than one. In this and otherembodiments, IC module 108IC can be located on the rail side of arrays700 such the arrays 700 to which module 108IC are connected (arrays700-PA through 700-PΩ in this embodiment) are electrically connectedbetween module 108IC and outputs (e.g., SIO1 through SIOΩ) to the load.Here, module 108IC has Ω IO ports for connection to IO port 2 of eachmodule 108-N of arrays 700-PA through 700-PΩ. In the configurationdepicted here, module 108IC can perform interphase balancing byselectively connecting the one or more energy sources of module 108IC toone or more of the arrays 700-PA through 700-PΩ (or to no output, orequally to all outputs, if interphase balancing is not required). System100 can be controlled by control system 102 (not shown, see FIG. 1A).

FIG. 10B is a schematic diagram depicting an example embodiment ofmodule 108IC. In this embodiment module 108IC includes an energy source206 connected with energy buffer 204 that in turn is connected withswitch circuitry 603. Switch circuitry 603 can include switch circuitryunits 604-PA through 604-PΩ for independently connecting energy source206 to each of arrays 700-PA through 700-PΩ, respectively. Variousswitch configurations can be used for each unit 604, which in thisembodiment is configured as a half-bridge with two semiconductorswitches S7 and S8. Each half bridge is controlled by control lines118-3 from LCD 114. This configuration is similar to module 108Adescribed with respect to FIG. 3A. As described with respect toconverter 202, switch circuitry 603 can be configured in any arrangementand with any switch types (e.g., MOSFET, IGBT, Silicon, GaN, etc.)suitable for the requirements of the application.

Switch circuitry units 604 are coupled between positive and negativeterminals of energy source 206 and have an output that is connected toan IO port of module 108IC. Units 604-PA through 604-PΩ can becontrolled by control system 102 to selectively couple voltage +V_(IC)or −V_(IC) to the respective module I/O ports 1 through Ω. Controlsystem 102 can control switch circuitry 603 according to any desiredcontrol technique, including the PWM and hysteresis techniques mentionedherein. Here, control circuitry 102 is implemented as LCD 114 and MCD112 (not shown). LCD 114 can receive monitoring data or statusinformation from monitor circuitry of module 108IC. This monitoring dataand/or other status information derived from this monitoring data can beoutput to MCD 112 for use in system control as described herein. LCD 114can also receive timing information (not shown) for purposes ofsynchronization of modules 108 of the system 100 and one or more carriersignals (not shown), such as the sawtooth signals used in PWM (FIGS.8C-8D).

For interphase balancing, proportionally more energy from source 206 canbe supplied to any one or more of arrays 700-PA through 700-PQ that isrelatively low on charge as compared to other arrays 700. Supply of thissupplemental energy to a particular array 700 allows the energy outputof those cascaded modules 108-1 thru 108-N in that array 700 to bereduced relative to the unsupplied phase array(s).

For example, in some example embodiments applying PWM, LCD 114 can beconfigured to receive the normalized voltage reference signal (Vrn)(from MCD 112) for each of the one or more arrays 700 that module 1081Cis coupled to, e.g., VrnPA through VrnPΩ. LCD 114 can also receivemodulation indexes MiPA through MiPΩ for the switch units 604-PA through604-PQ for each array 700, respectively, from MCD 112. LCD 114 canmodulate (e.g., multiply) each respective Vrn with the modulation indexfor the switch section coupled directly to that array (e.g., VrnAmultiplied by MiA) and then utilize a carrier signal to generate thecontrol signal(s) for each switch unit 604. In other embodiments, MCD112 can perform the modulation and output modulated voltage referencewaveforms for each unit 604 directly to LCD 114 of module 1081C. Instill other embodiments, all processing and modulation can occur by asingle control entity that can output the control signals directly toeach unit 604.

This switching can be modulated such that power from energy source 206is supplied to the array(s) 700 at appropriate intervals and durations.Such methodology can be implemented in various ways.

Based on the collected status information for system 100, such as thepresent capacity (Q) and SOC of each energy source in each array, MCD112 can determine an aggregate charge for each array 700 (e.g.,aggregate charge for an array can be determined as the sum of capacitytimes SOC for each module of that array). MCD 112 can determine whethera balanced or unbalanced condition exists (e.g., through the use ofrelative difference thresholds and other metrics described herein) andgenerate modulation indexes MiPA through MiPΩ accordingly for eachswitch unit 604-PA through 604-PQ.

During balanced operation, Mi for each switch unit 604 can be set at avalue that causes the same or similar amount of net energy over time tobe supplied by energy source 206 and/or energy buffer 204 to each array700. For example, Mi for each switch unit 604 could be the same orsimilar, and can be set at a level or value that causes the module 108ICto perform a net or time average discharge of energy to the one or morearrays 700-PA through 700-PΩ during balanced operation, so as to drainmodule 108IC at the same rate as other modules 108 in system 100. Insome embodiments, Mi for each unit 604 can be set at a level or valuethat does not cause a net or time average discharge of energy duringbalanced operation (causes a net energy discharge of zero). This can beuseful if module 108IC has a lower aggregate charge than other modulesin the system.

When an unbalanced condition occurs between arrays 700, then themodulation indexes of system 100 can be adjusted to cause convergencetowards a balanced condition or to minimize further divergence. Forexample, control system 102 can cause module 108IC to discharge more tothe array 700 with low charge than the others, and can also causemodules 108-1 through 108-N of that low array 700 to dischargerelatively less (e.g., on a time average basis). The relative net energycontributed by module 108IC increases as compared to the modules 108-1through 108-N of the array 700 being assisted, and also as compared tothe amount of net energy module 108IC contributes to the other arrays.This can be accomplished by increasing Mi for the switch unit 604supplying that low array 700, and by decreasing the modulation indexesof modules 108-1 through 108-N of the low array 700 in a manner thatmaintains Vout for that low array at the appropriate or required levels,and maintaining the modulation indexes for other switch units 604supplying the other higher arrays relatively unchanged (or decreasingthem).

The configuration of module 108IC in FIGS. 10A-10B can be used alone toprovide interphase or interarray balancing for a single system, or canbe used in combination with one or more other modules 1081C each havingan energy source and one or more switch portions 604 coupled to one ormore arrays. For example, a module 108IC with Ω switch portions 604coupled with Ω different arrays 700 can be combined with a second module108IC having one switch portion 604 coupled with one array 700 such thatthe two modules combine to service a system 100 having Ω+1 arrays 700.Any number of modules 108IC can be combined in this fashion, eachcoupled with one or more arrays 700 of system 100.

Furthermore, IC modules can be configured to exchange energy between twoor more subsystems of system 100. FIG. 10C is a block diagram depictingan example embodiment of system 100 with a first subsystem 1000-1 and asecond subsystem 1000-2 interconnected by IC modules. Specifically,subsystem 1000-1 is configured to supply three-phase power, PA, PB, andPC, to a first load (not shown) by way of system 110 ports SIO1, SIO2,and SIO3, while subsystem 1000-2 is configured to supply three-phasepower PD, PE, and PF to a second load (not shown) by way of system 110ports SIO4, SIO5, and SIO06, respectively. For example, subsystems1000-1 and 1000-2 can be configured as different packs supplying powerfor different motors of an EV or as different racks supplying power fordifferent microgrids.

In this embodiment each module 1081C is coupled with a first array ofsubsystem 1000-1 (via IO port 1) and a first array of subsystem 1000-2(via IO port 2), and each module 1081C can be electrically connectedwith each other module 1081C by way of I/O ports 3 and 4, which arecoupled with the energy source 206 of each module 1081C as describedwith respect to module 108C of FIG. 3C. This connection places sources206 of modules 1081C-1, 1081C-2, and 1081C-3 in parallel, and thus theenergy stored and supplied by modules 1081C is pooled together by thisparallel arrangement. Other arrangements such as serious connections canalso be used. Modules 1081C are housed within a common enclosure ofsubsystem 1000-1, however the interconnection modules can be external tothe common enclosure and physically located as independent entitiesbetween the common enclosures of both subsystems 1000.

Each module 1081C has a switch unit 604-1 coupled with IO port 1 and aswitch unit 604-2 coupled with I/O port 2, as described with respect toFIG. 10B. Thus, for balancing between subsystems 1000 (e.g., interpackor inter-rack balancing), a particular module 108IC can supplyrelatively more energy to either or both of the two arrays to which itis connected (e.g., module 1081C-1 can supply to array 700-PA and/orarray 700-PD). The control circuitry can monitor relative parameters(e.g., SOC and temperature) of the arrays of the different subsystemsand adjust the energy output of the IC modules to compensate forimbalances between arrays or phases of different subsystems in the samemanner described herein as compensating for imbalances between twoarrays of the same rack or pack. Because all three modules 1081C are inparallel, energy can be efficiently exchanged between any and all arraysof system 100. In this embodiment, each module 1081C supplies two arrays700, but other configurations can be used including a single IC modulefor all arrays of system 100 and a configuration with one dedicated ICmodule for each array 700 (e.g., six IC modules for six arrays, whereeach IC module has one switch unit 604). In all cases with multiple ICmodules, the energy sources can be coupled together in parallel so as toshare energy as described herein.

In systems with IC modules between phases, interphase balancing can alsobe performed by neutral point shifting (or common mode injection) asdescribed above. Such a combination allows for more robust and flexiblebalancing under a wider range of operating conditions. System 100 candetermine the appropriate circumstances under which to performinterphase balancing with neutral point shifting alone, interphaseenergy injection alone, or a combination of both simultaneously.

IC modules can also be configured to supply power to one or moreauxiliary loads 301 (at the same voltage as source 206) and/or one ormore auxiliary loads 302 (at voltages stepped down from source 302).FIG. 10D is a block diagram depicting an example embodiment of athree-phase system 100 A with two modules 108IC connected to performinterphase balancing and to supply auxiliary loads 301 and 302. FIG. 10Eis a schematic diagram depicting this example embodiment of system 100with emphasis on modules 108IC-1 and 108IC-2. Here, control circuitry102 is again implemented as LCD 114 and MCD 112 (not shown). The LCDs114 can receive monitoring data from modules 108IC (e.g., SOC of ES1,temperature of ES1, Q of ES1, voltage of auxiliary loads 301 and 302,etc.) and can output this and/or other monitoring data to MCD 112 foruse in system control as described herein. Each module 108IC can includea switch portion 602A (or 602B described with respect to FIG. 6C) foreach load 302 being supplied by that module, and each switch portion 602can be controlled to maintain the requisite voltage level for load 302by LCD 114 either independently or based on control input from MCD 112.In this embodiment, each module 108IC includes a switch portion 602Aconnected together to supply the one load 302, although such is notrequired.

FIG. 10F is a block diagram depicting another example embodiment of athree-phase system configured to supply power to one or more auxiliaryloads 301 and 302 with modules 108IC-1, 108IC-2, and 108IC-3. In thisembodiment, modules 108IC-1 and 108IC-2 are configured in the samemanner as described with respect to FIGS. 10D-10E. Module 108IC-3 isconfigured in a purely auxiliary role and does not actively injectvoltage or current into any array 700 of system 100. In this embodiment,module 108IC-3 can be configured like module 108C of FIG. 3B, having aconverter 202B,C (FIGS. 6B-6C) with one or more auxiliary switchportions 602A, but omitting switch portion 601. As such, the one or moreenergy sources 206 of module 108IC-3 are interconnected in parallel withthose of modules 108IC-1 and 108IC-2, and thus this embodiment of system100 is configured with additional energy for supplying auxiliary loads301 and 302, and for maintaining charge on the sources 206A of modules108IC-1 and 108IC-2 through the parallel connection with the source 206of module 108IC-3.

The energy source 206 of each IC module can be at the same voltage andcapacity as the sources 206 of the other modules 108-1 through 108-N ofthe system, although such is not required. For example, a relativelyhigher capacity can be desirable in an embodiment where one module 108ICapplies energy to multiple arrays 700 (FIG. 10A) to allow the IC moduleto discharge at the same rate as the modules of the phase arraysthemselves. If the module 108IC is also supplying an auxiliary load,then an even greater capacity may be desired so as to permit the ICmodule to both supply the auxiliary load and discharge at relatively thesame rate as the other modules.

Various aspects of the present subject matter are set forth below, inreview of, and/or in supplementation to, the embodiments described thusfar, with the emphasis here being on the interrelation andinterchangeability of the following embodiments. In other words, anemphasis is on the fact that each feature of the embodiments can becombined with each and every other feature unless explicitly stated ortaught otherwise.

In many embodiments, a method of controlling a modular energy system isprovided, including: monitoring status information of a plurality ofmodules in an array; determining a module status value for each modulein the plurality of modules based on the status information; anddetermining a modulation index for each module of the plurality ofmodules based on the module status values of the plurality of modulesand a voltage requirement for the array.

In some embodiments, the status information includes a state of chargeassociated with each module and a temperature associated with eachmodule. Monitoring status information can include measuring state ofcharge with monitor circuitry and measuring temperature with monitorcircuitry. Monitoring status information can include estimating state ofcharge with a model and estimating temperature with a model. The statusinformation can further include a capacity associated with each module.Determining the module status value for each module can includedetermining a single module status value that is representative of atleast the state of charge condition and the temperature condition of themodule. Determining the single module status value can include weightingat least one of the state of charge condition and the temperaturecondition.

In some embodiments, determining the module status value includesevaluating the status information against a threshold or condition. Thethreshold or condition can include at least one of a state of chargethreshold or a temperature threshold.

In some embodiments, the voltage requirement for the array is a peakvoltage for the array.

In some embodiments, determining the modulation index for each modulecan include determining the modulation index for each module based onthe module status values of the plurality of modules, a voltage of eachmodule, and a voltage requirement for the array. The voltage of eachmodule can be measured with monitor circuitry. The voltage of eachmodule can be estimated based on at least one of a state of charge ofthe module and current of the module.

In some embodiments, determining the modulation index for each modulecan include distributing the voltage requirement for the array acrossthe modules of the array based on the module status value of each moduleof the array.

In some embodiments, the method can further include communicating themodulation index for each module and a normalized reference signal forthe array from a master control device of the system to a plurality oflocal control devices associated with the plurality of modules.

In some embodiments, the method can further include, for each module ofthe plurality of modules, modulating a normalized reference signal forthe array with the modulation index of the module and communicating themodulated reference signal from a master control device of the system toa local control devices associated with the module.

In some embodiments, the plurality of modules are electrically connectedtogether in the array to output an AC voltage signal including asuperposition of output voltages from each of the plurality of modules,where each of the plurality of modules includes an energy source and aconverter. Each module can further include monitor circuitry configuredto monitor the status information of the module, where each module isconfigured to output the status information to a control system, andwhere the control system is configured to control the converter of eachmodule based on the status information.

In some embodiments, the method further includes using the modulationindex of each module to control each module to output a voltageaccording to a pulse width modulation technique.

In some embodiments, the plurality of modules is a first plurality ofmodules in the array is a first array, and the method further includes:monitoring status information of a second plurality of modules in asecond array; determining a module status value for each module in thesecond plurality of modules based on the status information; anddetermining a modulation index for each module of the second pluralityof modules based on the module status values of the second plurality ofmodules and a voltage requirement for the second array. The method canfurther include: assessing a status of the first array and a status ofthe second array based on the module status values of the first arrayand the second array; and performing common mode injection to shift aneutral point between the first array and the second array. Assessingthe status of the first array and the status of the second array caninclude comparing a sum of the module status values of the firstplurality of modules to a sum of the module status values of the secondplurality of modules. The sum of the module status values of the firstplurality of modules can be less than the sum of the module statusvalues of the second plurality of modules, and common mode injection canbe performed to shift the neutral point from the second array towardsthe first array.

In many embodiments, a method of controlling a modular energy system isprovided, the system having a first array and a second array, each arrayincluding a plurality of modules electrically connected together in thearray to output an AC voltage signal including a superposition of outputvoltages from each of the plurality of modules, where each of theplurality of modules includes an energy source and a converter, themethod including: monitoring status information of the modules of thefirst array and the modules of the second array; determining a modulestatus value for each module of the first array and the second arraybased on the status information; and assessing a difference in statusbetween the first array and the second array based on the module statusvalues.

In some embodiments, the method can further include performing commonmode injection to reference signals of the first and second arrays basedon the assessed difference. The method can further include: determininga modulation index for each module of the first array based on themodule status values of the modules of the first array and a voltagerequirement of the first array; and determining a modulation index foreach module of the second array based on the module status values of themodules of the second array and a voltage requirement of the secondarray.

In some embodiments, the status information includes a state of chargeassociated with each module and a temperature associated with eachmodule. The status information can further include a capacity associatedwith each module. Determining the module status value for each modulecan include determining a single module status value that isrepresentative of at least the state of charge condition and thetemperature condition of the module. Determining the single modulestatus value can include weighting at least one of the state of chargecondition and the temperature condition.

In some embodiments, determining the module status value includesevaluating the status information against a threshold or condition. Thethreshold or condition can include at least one of a state of chargethreshold or a temperature threshold.

In some embodiments, the system further includes a third array includinga plurality of modules electrically connected together in the thirdarray to output an AC voltage signal including a superposition of outputvoltages from each of the plurality of modules, where each of theplurality of modules includes an energy source and a converter. Themethod can further include: determining a module status value for eachmodule of the third array based on the status information; and assessinga difference in status between the first array, the second array, andthe third array based on the module status values. In some embodiments,the method can further include performing common mode injection toreference signals of the first, second, and third arrays based on theassessed difference.

In many embodiments, a computer readable medium is provided, the mediumstoring a plurality of instructions that, when executed by processingcircuitry, cause the processing circuitry to perform steps, including:monitoring status information of a plurality of modules in an array;determining a module status value for each module in the plurality ofmodules based on the status information; and determining a modulationindex for each module of the plurality of modules based on the modulestatus values of the plurality of modules and a voltage requirement forthe array.

In some embodiments, the status information includes a state of chargeassociated with each module and a temperature associated with eachmodule. In some embodiments, where monitoring status informationincludes measuring state of charge with monitor circuitry and measuringtemperature with monitor circuitry. In some embodiments, monitoringstatus information includes estimating state of charge with a model andestimating temperature with a model. The status information can furtherinclude a capacity associated with each module. Determining the modulestatus value for each module can include determining a single modulestatus value that is representative of at least the state of chargecondition and the temperature condition of the module. Determining thesingle module status value can include weighting at least one of thestate of charge condition and the temperature condition.

In some embodiments, determining the module status value includesevaluating the status information against a threshold or condition. Thethreshold or condition can include at least one of a state of chargethreshold or a temperature threshold.

In some embodiments, the voltage requirement for the array is a peakvoltage for the array.

In some embodiments, determining the modulation index for each moduleincludes determining the modulation index for each module based on themodule status values of the plurality of modules, a voltage of eachmodule, and a voltage requirement for the array.

In some embodiments, determining the modulation index for each moduleincludes distributing the voltage requirement for the array across themodules of the array based on the module status value of each module ofthe array.

In some embodiments, the plurality of instructions cause the processingcircuitry to perform additional steps including using the modulationindex of each module to control each module to output a voltageaccording to a pulse width modulation technique.

In some embodiments, the plurality of modules is a first plurality ofmodules in the array is a first array, and the plurality of instructionscause the processing circuitry to perform additional steps including:monitoring status information of a second plurality of modules in asecond array; determining a module status value for each module in thesecond plurality of modules based on the status information; anddetermining a modulation index for each module of the second pluralityof modules based on the module status values of the second plurality ofmodules and a voltage requirement for the second array. The plurality ofinstructions can cause the processing circuitry to perform additionalsteps including: assessing a status of the first array and a status ofthe second array based on the module status values of the first arrayand the second array; and causing the performance of common modeinjection to shift a neutral point between the first array and thesecond array. Assessing the status of the first array and the status ofthe second array can include comparing a sum of the module status valuesof the first plurality of modules to a sum of the module status valuesof the second plurality of modules.

In many embodiments, a computer readable medium is provided, the mediumstoring a plurality of instructions that, when executed by processingcircuitry, cause the processing circuitry to perform steps including:monitoring status information of modules of a first array and modules ofa second array; determining a module status value for each module of thefirst array and the second array based on the status information; andassessing a difference in status between the first array and the secondarray based on the module status values.

In some embodiments, the modules of the first array each includes anenergy source and a converter and are electrically connected together tooutput an AC voltage signal including a superposition of output voltagesfrom each of the modules of the first array, and where the modules ofthe second array each includes an energy source and a converter and areelectrically connected together to output an AC voltage signal includinga superposition of output voltages from each of the modules of thesecond array.

In some embodiments, the plurality of instructions, when executed,further cause the processing circuitry to cause performance of commonmode injection to reference signals of the first and second arrays basedon the assessed difference.

In some embodiments, the plurality of instructions, when executed,further cause the processing circuitry to perform steps including:determining a modulation index for each module of the first array basedon the module status values of the modules of the first array and avoltage requirement of the first array; and determining a modulationindex for each module of the second array based on the module statusvalues of the modules of the second array and a voltage requirement ofthe second array.

In some embodiments, the status information includes a state of chargeassociated with each module and a temperature associated with eachmodule. Determining the module status value for each module can includedetermining a single module status value that is representative of atleast the state of charge condition and the temperature condition of themodule. Determining the single module status value can include weightingat least one of the state of charge condition and the temperaturecondition.

In some embodiments, the plurality of instructions, when executed,further cause the processing circuitry to perform steps including:determining a module status value for each module of a third array basedon the status information; and assessing a difference in status betweenthe first array, the second array, and the third array based on themodule status values. The plurality of instructions, when executed, canfurther cause the processing circuitry to cause performance of commonmode injection to reference signals of the first, second, and thirdarrays based on the assessed difference. The plurality of instructions,when executed, can further cause the processing circuitry to causeperformance of energy injection from an interconnection module to atleast one of the first, second, and third arrays based on the assesseddifference.

In many embodiments, a modular energy system is provided, the systemincluding: a control system configured to: monitor status information ofa plurality of modules in an array; determine a module status value foreach module in the plurality of modules based on the status information;and determine a modulation index for each module of the plurality ofmodules based on the module status values of the plurality of modulesand a voltage requirement for the array.

In some embodiments, the status information includes a state of chargeassociated with each module and a temperature associated with eachmodule. The system can further include monitor circuitry to measurestate of charge and temperature associated with each module. The controlsystem can be configured to estimate state of charge with a model andestimate temperature with a model. The status information can furtherinclude a capacity associated with each module. The control system canbe configured to determine a single module status value that isrepresentative of at least the state of charge condition and thetemperature condition of the module. The control system can beconfigured to weight at least one of the state of charge condition andthe temperature condition.

In some embodiments, the control system can be configured to evaluatethe status information against a threshold or condition. The thresholdor condition can include at least one of a state of charge threshold ora temperature threshold.

In some embodiments, the voltage requirement for the array is a peakvoltage for the array.

In some embodiments, the control system is configured to determine themodulation index for each module based on the module status values ofthe plurality of modules, a voltage of each module, and a voltagerequirement for the array.

In some embodiments, the control system is configured to algorithmicallydistribute the voltage requirement for the array across the modules ofthe array based on the module status value of each module of the array.

In some embodiments, the control system is configured to use themodulation index of each module to control each module to output avoltage according to a pulse width modulation technique.

In some embodiments, the system further includes the plurality ofmodules in the array.

In many embodiments, a modular energy system is provided, the systemincluding: a control system configured to: monitor status information ofa plurality of modules of a first array and a plurality of modules of asecond array; determine a module status value for each module of thefirst array and the second array based on the status information; andassess a difference in status between the first array and the secondarray based on the module status values.

In some embodiments, the system further includes the plurality ofmodules of the first array and the plurality of modules of the secondarray, where the plurality of modules of the first array each includesan energy source and a converter and are electrically connected togetherto output an AC voltage signal including a superposition of outputvoltages from each of the modules of the first array, and where theplurality of modules of the second array each includes an energy sourceand a converter and are electrically connected together to output an ACvoltage signal including a superposition of output voltages from each ofthe modules of the second array.

In some embodiments, the control system is configured to causeperformance of common mode injection to reference signals of the firstand second arrays based on the assessed difference.

In some embodiments, the control system is configured to: determine amodulation index for each module of the first array based on the modulestatus values of the modules of the first array and a voltagerequirement of the first array; and determine a modulation index foreach module of the second array based on the module status values of themodules of the second array and a voltage requirement of the secondarray.

In some embodiments, the status information includes a state of chargeassociated with each module and a temperature associated with eachmodule. The control system can be configured to determine a singlemodule status value that is representative of at least the state ofcharge condition and the temperature condition of the module. In someembodiments, the control system can be configured to weight at least oneof the state of charge condition and the temperature condition.

In some embodiments, the system further includes a third array includinga plurality of modules electrically connected together in the thirdarray to output an AC voltage signal including a superposition of outputvoltages from each of the plurality of modules, where each of theplurality of modules includes an energy source and a converter. Thecontrol system can be configured to: determine a module status value foreach module of the third array based on the status information; andassess a difference in status between the first array, the second array,and the third array based on the module status values. The controlsystem can be configured to cause performance of common mode injectionto reference signals of the first, second, and third arrays based on theassessed difference. The control system can be configured to causeperformance of energy injection from an interconnection module to atleast one of the first, second, and third arrays based on the assesseddifference.

The term “module” as used herein refers to one of two or more devices orsub-systems within a larger system. The module can be configured to workin conjunction with other modules of similar size, function, andphysical arrangement (e.g., location of electrical terminals,connectors, etc.). Modules having the same function and energy source(s)can be configured identical (e.g., size and physical arrangement) to allother modules within the same system (e.g., rack or pack), while moduleshaving different functions or energy source(s) may vary in size andphysical arrangement. While each module may be physically removable andreplaceable with respect to the other modules of the system (e.g., likewheels on a car, or blades in an information technology (IT) bladeserver), such is not required. For example, a system may be packaged ina common housing that does not permit removal and replacement any onemodule, without disassembly of the system as a whole. However, any andall embodiments herein can be configured such that each module isremovable and replaceable with respect to the other modules in aconvenient fashion, such as without disassembly of the system.

The term “master control device” is used herein in a broad sense anddoes not require implementation of any specific protocol such as amaster and slave relationship with any other device, such as the localcontrol device.

The term “output” is used herein in a broad sense, and does not precludefunctioning in a bidirectional manner as both an output and an input.Similarly, the term “input” is used herein in a broad sense, and doesnot preclude functioning in a bidirectional manner as both an input andan output.

The terms “terminal” and “port” are used herein in a broad sense, can beeither unidirectional or bidirectional, can be an input or an output,and do not require a specific physical or mechanical structure, such asa female or male configuration.

Different reference number notations are used herein. These notationsfacilitate the description of the present subject matter and do notlimit the scope of that subject matter. Generally, a genus of elementsis referred to with a number, e.g., “123”, and a subgenus thereof isreferred to with a letter appended to the number, e.g., 123A or 123B.References to the genus without the letter appendix (e.g., 123) refersto the genus as a whole, inclusive of all subgenuses. Some figures showmultiple instances of the same element. Those elements may be appendedwith a number or a letter in a “-X” format, e.g., 123-1, 123-2, or123-PA. This -X format does not imply that the elements must beconfigured identically in each instance, but is rather used tofacilitate differentiation when referencing the elements in the figures.Reference to the genus 123 without the -X appendix broadly refers to allinstances of the element within the genus.

Various aspects of the present subject matter are set forth below, inreview of, and/or in supplementation to, the embodiments described thusfar, with the emphasis here being on the interrelation andinterchangeability of the following embodiments. In other words, anemphasis is on the fact that each feature of the embodiments can becombined with each and every other feature unless explicitly statedotherwise or logically implausible.

Processing circuitry can include one or more processors,microprocessors, controllers, and/or microcontrollers, each of which canbe a discrete or stand-alone chip or distributed amongst (and a portionof) a number of different chips. Any type of processing circuitry can beimplemented, such as, but not limited to, personal computingarchitectures (e.g., such as used in desktop PC's, laptops, tablets,etc.), programmable gate array architectures, proprietary architectures,custom architectures, and others. Processing circuitry can include adigital signal processor, which can be implemented in hardware and/orsoftware. Processing circuitry can execute software instructions storedon memory that cause processing circuitry to take a host of differentactions and control other components.

Processing circuitry can also perform other software and/or hardwareroutines. For example, processing circuitry can interface withcommunication circuitry and perform analog-to-digital conversions,encoding and decoding, other digital signal processing, multimediafunctions, conversion of data into a format (e.g., in-phase andquadrature) suitable for provision to communication circuitry, and/orcan cause communication circuitry to transmit the data (wired orwirelessly).

Any and all communication signals described herein can be communicatedwirelessly except where noted or logically implausible. Communicationcircuitry can be included for wireless communication. The communicationcircuitry can be implemented as one or more chips and/or components(e.g., transmitter, receiver, transceiver, and/or other communicationcircuitry) that perform wireless communications over links under theappropriate protocol (e.g., Wi-Fi, Bluetooth, Bluetooth Low Energy, NearField Communication (NFC), Radio Frequency Identification (RFID),proprietary protocols, and others). One or more other antennas can beincluded with communication circuitry as needed to operate with thevarious protocols and circuits. In some embodiments, communicationcircuitry can share antenna for transmission over links. RFcommunication circuitry can include a transmitter and a receiver (e.g.,integrated as a transceiver) and associated encoder logic.

Processing circuitry can also be adapted to execute the operating systemand any software applications, and perform those other functions notrelated to the processing of communications transmitted and received.

Computer program instructions for carrying out operations in accordancewith the described subject matter may be written in any combination ofone or more programming languages, including an object orientedprogramming language such as Java, JavaScript, Smalltalk, C++, C#,Transact-SQL, XML, PHP or the like and conventional proceduralprogramming languages, such as the “C” programming language or similarprogramming languages.

Memory, storage, and/or computer readable media can be shared by one ormore of the various functional units present, or can be distributedamongst two or more of them (e.g., as separate memories present withindifferent chips). Memory can also reside in a separate chip of its own.

To the extent the embodiments disclosed herein include or operate inassociation with memory, storage, and/or computer readable media, thenthat memory, storage, and/or computer readable media are non-transitory.Accordingly, to the extent that memory, storage, and/or computerreadable media are covered by one or more claims, then that memory,storage, and/or computer readable media is only non-transitory. Theterms “non-transitory” and “tangible” as used herein, are intended todescribe memory, storage, and/or computer readable media excludingpropagating electromagnetic signals, but are not intended to limit thetype of memory, storage, and/or computer readable media in terms of thepersistency of storage or otherwise. For example, “non-transitory”and/or “tangible” memory, storage, and/or computer readable mediaencompasses volatile and non-volatile media such as random access media(e.g., RAM, SRAM, DRAM, FRAM, etc.), read-only media (e.g., ROM, PROM,EPROM, EEPROM, flash, etc.) and combinations thereof (e.g., hybrid RAMand ROM, NVRAM, etc.) and variants thereof.

It should be noted that all features, elements, components, functions,and steps described with respect to any embodiment provided herein areintended to be freely combinable and substitutable with those from anyother embodiment. If a certain feature, element, component, function, orstep is described with respect to only one embodiment, then it should beunderstood that that feature, element, component, function, or step canbe used with every other embodiment described herein unless explicitlystated otherwise. This paragraph therefore serves as antecedent basisand written support for the introduction of claims, at any time, thatcombine features, elements, components, functions, and steps fromdifferent embodiments, or that substitute features, elements,components, functions, and steps from one embodiment with those ofanother, even if the following description does not explicitly state, ina particular instance, that such combinations or substitutions arepossible. It is explicitly acknowledged that express recitation of everypossible combination and substitution is overly burdensome, especiallygiven that the permissibility of each and every such combination andsubstitution will be readily recognized by those of ordinary skill inthe art.

As used herein and in the appended claims, the singular forms “a,” “an,”and “the” include plural referents unless the context clearly dictatesotherwise.

While the embodiments are susceptible to various modifications andalternative forms, specific examples thereof have been shown in thedrawings and are herein described in detail. It should be understood,however, that these embodiments are not to be limited to the particularform disclosed, but to the contrary, these embodiments are to cover allmodifications, equivalents, and alternatives falling within the spiritof the disclosure. Furthermore, any features, functions, steps, orelements of the embodiments may be recited in or added to the claims, aswell as negative limitations that define the inventive scope of theclaims by features, functions, steps, or elements that are not withinthat scope.

1. A method of controlling a modular energy system, comprising:monitoring status information of a plurality of modules in an array,wherein the plurality of modules are electrically connected together inthe array to output an AC voltage signal comprising a superposition ofoutput voltages from each of the plurality of modules, wherein each ofthe plurality of modules comprises an energy source and a converter,wherein the status information comprises at least one of state of chargeand temperature, and wherein a control system is configured to controlthe converter of each module based on the status information;determining a module status value for each module in the plurality ofmodules based on the status information; and determining a modulationindex for each module of the plurality of modules based on the modulestatus values of the plurality of modules and a voltage requirement forthe array.
 2. The method of claim 1, wherein monitoring statusinformation comprises measuring state of charge with monitor circuitryand measuring temperature with monitor circuitry.
 3. The method of claim2, wherein monitoring status information comprises estimating state ofcharge with a model and estimating temperature with a model.
 4. Themethod of claim 1, wherein the status information further comprises acapacity associated with each module.
 5. The method of claim 1, whereindetermining the module status value for each module comprisesdetermining a single module status value that is representative of atleast the state of charge condition and the temperature condition of themodule.
 6. The method of claim 5, wherein determining the single modulestatus value comprises weighting at least one of the state of chargecondition and the temperature condition.
 7. The method of claim 1,wherein determining the module status value comprises evaluating thestatus information against a threshold or condition.
 8. The method ofclaim 7, wherein the threshold or condition comprises at least one of astate of charge threshold or a temperature threshold.
 9. The method ofclaim 1, wherein the voltage requirement for the array is a peak voltagefor the array.
 10. The method of claim 1, wherein determining themodulation index for each module comprises determining the modulationindex for each module based on the module status values of the pluralityof modules, a voltage of each module, and a voltage requirement for thearray.
 11. The method of claim 10, wherein the voltage of each module ismeasured with monitor circuitry.
 12. The method of claim 11, wherein thevoltage of each module is estimated based on at least one of a state ofcharge of the module and current of the module.
 13. The method of claim1, wherein determining the modulation index for each module comprisesdistributing the voltage requirement for the array across the modules ofthe array based on the module status value of each module of the array.14. The method of claim 1, further comprising communicating themodulation index for each module and a normalized reference signal forthe array from a master control device of the system to a plurality oflocal control devices associated with the plurality of modules.
 15. Themethod of claim 1, further comprising, for each module of the pluralityof modules, modulating a normalized reference signal for the array withthe modulation index of the module and communicating the modulatedreference signal from a master control device of the system to a localcontrol device associated with the module.
 16. The method of claim 1,further comprising using the modulation index of each module to controleach module to output a voltage according to a pulse width modulationtechnique.
 17. The method of claim 1, wherein the plurality of modulesis a first plurality of modules and the array is a first array, themethod further comprising: monitoring status information of a secondplurality of modules in a second array; determining a module statusvalue for each module in the second plurality of modules based on thestatus information; and determining a modulation index for each moduleof the second plurality of modules based on the module status values ofthe second plurality of modules and a voltage requirement for the secondarray.
 18. The method of claim 17, further comprising: assessing astatus of the first array and a status of the second array based on themodule status values of the first array and the second array; andperforming common mode injection to shift a neutral point between thefirst array and the second array.
 19. The method of claim 18, whereinassessing the status of the first array and the status of the secondarray comprises comparing a sum of the module status values of the firstplurality of modules to a sum of the module status values of the secondplurality of modules.
 20. The method of claim 19, wherein the sum of themodule status values of the first plurality of modules is less than thesum of the module status values of the second plurality of modules, andwherein common mode injection is performed to shift the neutral pointfrom the second array towards the first array.
 21. A computer readablemedium storing a plurality of instructions that, when executed byprocessing circuitry, cause the processing circuitry to perform steps,comprising: monitoring status information of a plurality of modules inan array; determining a module status value for each module in theplurality of modules based on the status information; and determining amodulation index for each module of the plurality of modules based onthe module status values of the plurality of modules and a voltagerequirement for the array.
 22. A modular energy system, comprising: acontrol system configured to: monitor status information of a pluralityof modules in an array; determine a module status value for each modulein the plurality of modules based on the status information; anddetermine a modulation index for each module of the plurality of modulesbased on the module status values of the plurality of modules and avoltage requirement for the array.